Sret Return From Subroutine and Skip | Samsung KS57C2308 manual

SAM47 INSTRUCTION SETKS57C2308/P2308/C2316/P2316

SRET — Return From Subroutine and Skip

SRET

Operation:	Operand	Operation Summary	Bytes	Cycles

	–	Return from subroutine and skip	1	3 + S

Description: SRET is normally used to return to the previously executing procedure at the end of a subroutine that was initiated by a CALL or CALLS instruction. SRET skips the resulting address, which is generally the instruction immediately after the point at which the subroutine was called. Then, program execution continues from the resulting address and the contents of the location addressed by the stack pointer are popped into the program counter.

Operand			Binary Code						Operation Notation

–	1	1	1	0	0	1	0	1	PC13–8 ← (SP + 1) (SP)
									PC7–0 ← (SP + 3) (SP + 2)
									EMB,ERB ← (SP + 4)
									SP ← SP + 6

Example: If the stack pointer contains the value 0FAH and RAM locations 0FAH, 0FBH, 0FCH, and 0FDH contain the values 1H, 0H, 5H, and 2H, respectively, the instruction

SRET

leaves the stack pointer with the value 00H and the program returns to continue execution at location 0125H, then skips unconditionally.

During a return from subroutine, data is popped from the stack to the PC as follows:

SP → (0FAH)		PC11–PC8

SP + 1 (0FBH)	0	0	PC13	PC12

SP + 2(0FCH)		PC3–PC0

SP + 3(0FDH)		PC7–PC4

SP + 4(0FEH)	0	0	EMB	ERB

SP + 5(0FFH)	0	0	0	0
SP + 6(00H)
SP + 6(00H)

5-86

Image 160

Samsung KS57C2308 manual Sret Return From Subroutine and Skip

Contents

Product Overview Overview Pins Bit Basic TimerBit Timer/Counter Watch Timer Block Diagram KS57C2308 INT4 INT0INT1 INT2 Test signal input must be connected to V SS Test PIN Circuit Diagrams Pin Circuit Type E P4, P5 Address Spaces OverviewGeneral-Purpose Program Memory Vector Addresses GENERAL-PURPOSE Memory Areas Vector Address AreaEMB ERB PC9 PC8 PC7 PC6 PC5 PC4 PC3 PC2 PC1 PC0 + Programming TIP Defining Vectored Interrupts + Programming TIP Using the REF Look-Up Table Instruction Reference Area Data Memory RAM Memory Banks 0, 1, F80H-FFFHData Memory Addressing Modes Working Registers + Programming TIP Clearing Data Memory Banks 0 Ramclr SMBRMCL1 @HL,A Incs SMB RMCL0 @HL,A Incs Working Registers Working Register Map Working Register Banks Paired Working Registers Special-Purpose Working Registers + Programming TIP Selecting the Working Register Area INT0 PushSRB Incs WX,EA YZ,EA POP Stack Pointer SP SP3 SP2 SP1SP7 SP6 SP5 SP4 + Programming TIP Initializing the Stack Pointer Push Operations Push InstructionsCall Instructions Interrupt Routines POP Operations POP InstructionsRET and Sret Instructions Iret Instructions BSC Register Organization Name Address Bit Program Counter PC MSB LSB FB0H IS1 IS0 EMB ERB FB1H SC2 SC1 SC0 Interrupt Status Flags IS0, IS1 Interrupt Status Flag Bit SettingsIS1 IS0 + Programming TIP Using the EMB Flag to Select Memory Banks EMB Flag EMB ERB Flag ERB HL,EA Carry Flag C Skip Condition Flags SC2, SC1, SC0Valid Carry Flag Manipulation Instructions Operation Type ADC EA,HL HL,#0AAHBand Address Spaces Addressing Modes RAM Address Structure EMB and ERB Initialization Values Reset Bitr EMB+ Programming TIP Initializing the EMB and ERB Flags EMB = Enable Memory Bank SettingsEMB-Independent Addressing Select Bank Register SB Select Memory Bank SMB Instruction BIT Addressing Direct and Indirect AddressingBank Mapping Bit Indirect Addressing @HL @WLAdata EQU Bdata EQU 8EH SMB Bdata EQU HL,#BDATA WX,#ADATA Comp @WLCpse @HL Sret Decs Comp RET Bit Indirect Addressing Example HL,#BDATA WX,#ADATA Trans @WLXchd @HL SMB HL,#BDATA WX,#ADATA Trans @WL EA,P4 SMB ADATA,EABDATA,EA Bdata EQU 8EH SMB EA,P4 HL,#ADATA EA,@HL SMB HL,#ADATA EA,@HL Memory MAP MAP for Hardware Registers I/O Map for Memory Bank Addressing Mode Register Bit FB7H Scmod FB8H INT a IE4 IRQ4 IEB IrqbFbah INT B IEW Irqw Fbch INT C IET0 IRQT0 Register Descriptions Register Description Format Read/Write Bit Addressing Basic Timer Restart Bit Bmod Basic Timer Mode RegisterBit Identifier FD0H Clmod Clock Output Mode RegisterClock Source and Frequency Selection Control Bits Fbeh IE0, 1, IRQ0, 1 INT0, 1 Interrupt Enable/Request FlagsIE1 IRQ1 IE0 IRQ0 Fbfh IE2, IRQ2 INT2 Interrupt Enable/Request FlagsIE2 IRQ2 IE4, IRQ4 INT4 Interrupt Enable/Request Flags IEB, Irqb Intb Interrupt Enable/Request FlagsFB8H IE4 IRQ4 IEB Irqb IES, Irqs Ints Interrupt Enable/Request Flags Ints Interrupt Enable FlagFbdh IES Irqs IET0, IRQT0 INTT0 Interrupt Enable/Request Flags INTT0 Interrupt Enable FlagFbch IET0 IRQT0 IEW, Irqw Intw Interrupt Enable/Request Flags Intw Interrupt Enable FlagFbah IEW Irqw External Interrupt Mode Control Bits IMOD0 External Interrupt 0 INT0 Mode RegisterFB4H IMOD1 External Interrupt 1 INT1 Mode Register FB5HIMOD1.0 External Interrupt 1 Edge Detection Control Bit IMOD2 External Interrupt 2 INT2 Mode Register FB6HIMOD2.2 IMOD2.1 IMOD2.0 External Interrupt 2 Edge Detection Selection Bit Interrupt Master Enable Bit IPR Interrupt Priority RegisterFB2H IME LCD Clock Output Disable/Enable Bit Lcon LCD Output Control RegisterF8EH Read/Write Bit Addressing LCD Bias Selection Bit Lmod LCD Mode Register F8DH, F8CHLCD Clock Lcdck Frequency Selection Bits Duty and Bias Selection for LCD Display Pcon Power Control Register Read/Write Bit Addressing CPU Operating Mode Control BitsFB3H CPU Clock Frequency Selection Bits PMG1 Port I/O Mode Flags Group 1 Port 3 FE9H, FE8H FEDH, Fech PMG2 Port I/O Mode Flags Group 2 Port 2, 4, 5,PM7 PM5 PM4 PM2 PNE N-Channel Open-Drain Mode Register FD7H, FD6H FB1H, FB0H PSW Program Status WordSC2-SC0 SC1 IS1 IS0 EMB ERB FDDH, Fdch Pumod Pull-Up Resistor Mode RegisterPUR7 PUR6 PUR5 PUR4 PUR3 PUR2 PUR1 PUR0 FB7H Scmod System Clock Mode Control Register1Bit Smod Serial I/O Mode Register FE1H, FE0H TMOD0 Timer/Counter 0 Mode Register F91H, F90H Timer/Counter 0 Input Clock Selection BitsEnable/Disable Timer/Counter 0 Bit Clear Counter and Resume Counting Control Bit TOE Timer Output Enable Flag Register Timer/Counter 0 Output Enable FlagTOE0 Bit3 Wdflag Watchdog Timer Counter Clear Flag Register Watchdog Timer Counter Clear FlagF9AH Wdtcf Wdmod Watchdog Timer Mode Register F99H, F98H Watchdog Timer Enable/Disable ControlWdmod 5AH Wmod Watch Timer Mode Register F89H, F88H Instruction SET Features SAM47 Instruction SET Instruction Reference Area Reducing Instruction Redundancy Bitr EMB Instructions Which Have Skip Conditions Flexible Bit ManipulationInstructions Which Affect the Carry Flag ADC A,@HL ADC and SBC Instruction Skip ConditionsSBC A,@HL Instruction Operand Notation Symbol Definition Symbols and Conventions Data Type SymbolsRegister Identifiers Full Register Name Opcode Definitions Opcode Definitions Direct RegisterOpcode Definitions Indirect Register @HL @WX @WL HIGH-LEVEL Summary Idle StopCpse EA,RR XCH EA,DAXchi @HL DA,A COM ADC @HLADS SBC @HL Btstz Bitr Binary Code Summary SCF RCF CCF First Byte Condition PC13-8 ← SP + 1 SP Ra,#im Ra ← im RR,#imm RR ← imm EA,RR EA ← EA or RR EA,RR EA ← EA and RREA,RR EA ← EA XOR RR ← a + HL + C Skip if C = Second Byte Bit Addresses FB0H-FBFH FF0H-FFFH LDB Instruction Descriptions ADC Add With Carry ADCOperation Operand Operation Summary Bytes Cycles Operand Binary Code Operation Notation #8H ← 8H ADS Add And Skip On Overflow ADSADS EA,HL JPS YYY EA ← 0C3H + 12H = 0D5H Logical Band Bit Logical BandSMB Band Band C,P1.@L Flag EQU Band @H+FLAG Bitr Bit Reset BitrFF1H-FF9H Bitr P2.0 BP2 Bitr Incs BP2 Bits Bits Bit SetBits P2.0 BP2 Bits BOR Bit Logical or BOR BOR @H+FLAG Btsf Bit Test and Skip on False BtsfLABEL2 LABEL3 BP2 Btsf RET Incs BP2 Btst Bit Test and Skip on True Btst BP2 Btst Btstz Btstz Bit Test and Skip on True Clear BitBP2 Btstz Btstz @H+FLAG Bits @H+FLAG Bxor Bxor Bit Exclusive orRCF Bxor C,P1.0 Bxor @H+FLAG Call Operation Call Call ProcedureOperand Operation Summary Bytes Cycles Calls Call Procedure Short Calls OperationCalls Play 0FFH 0FEH EMB, ERB 0FDH 0FCH 0FBH 0FAH CCF Complement Carry Flag CCF COM COM Complement AccumulatorCOM a Cpse Cpse Compare and Skip if EqualCpse EA,HL RET Decs Decrement and Skip on Borrow DecsDecs HL Call PLAY1 DI Disable Interrupts EI Enable Interrupts Idle Idle Idle OperationIdle NOP Incs Incs Increment and Skip on CarryIncs @HL Iret Return From Interrupt IretIS1 IS0 EMB ERB SC2 SC1 SC0 JP Jump JP OperationADR14 Jump to direct address 14 bits JPS Jump Short JPS OperationADR12 Jump direct in page 12 bits JR Jump Relative Very Short JR KK JPS AAA BBB CCC DDDEA,WX ADS WX,EA JPS YYY XXX LD LD Load Description Operand Binary Code Operation Notation Instruction Operation Description and Guidelines Examples Instruction Operation Description and Guidelines LDB Load Bit LDB Flag LDB @H+FLAGFlag EQU 20H.3 RCF LDB @H+FLAG,C LDC Load Code Byte LDCCall Display JPS Main ORG Display LDC ORG 01FDH Display LD01FFH LDC LDD Load Data Memory and Decrement LDD Operation LDI Operation LDI Load Data Memory and IncrementHL,#2FH LDI @HL NOP NOP No OperationStop NOP Or Logical or Or EA,@HL POP POP Pop From StackPOP HL Push Push Push Onto StackPush HL RCF Reset Carry Flag RCF Operation REF Reference InstructionOperand Operation Summary Bytes Cycles Memc Reference code BBB EA,#FFH CCC Call SUB1 DDD SUB2 BBB EA,#FFH CCC Tcall SUB1 DDD TJP SUB2AAA LD Opcode Symbol Instruction HL,#0FHTcall SUB1 TJP SUB2 ORG RET RET Return From SubroutinePSW ← EMB,ERB RRC RRC Rotate Accumulator Right Through CarryRRC a SBC Subtract With Carry SBCSCF SBC EA,HL RCF SBC EA,HL #8H SBS Subtract SBSRCF SBS EA,HL SCF SBS EA,HL SCF Set Carry Flag SCF SMB Select Memory Bank SMBAddresses Register Areas Bank Format Binary Code Operation Notation SRB Select Register Bank ERB Setting SRB Settings Selected Register BankSRB Sret Return From Subroutine and Skip Sret Stop Stop Operation Stop Vent Load EMB, ERB, and Vector Address VENTn VENTn Example The instruction sequence XCH XCH Exchange a or EA with Nibble or ByteXCH EA,@HL Xchd Operation Xchd Exchange and DecrementYYY Xchd @HL Xchi Exchange and Increment Xchi OperationHL,#2FH YYY Xchi @HL XOR XOR Logical Exclusive orXOR EA,HL SAM47 Instruction SET Oscillator Circuits Interrupts Power-Down Page Oscillator Circuits CPU Clock Notation Using a Subsystem Clock Clock Control Registers Clock Circuit Diagram STO Main System Oscillator Circuits Subsystem Oscillator Circuits Power Control Register Pcon Pcon Bit Settings Resulting CPU Operating ModePCON.1 PCON.0 SCMOD.0 = PCON,A + Programming TIP Setting the CPU ClockInstruction Cycle Times System Clock Mode Register Scmod FB7H SCMOD.3 SCMOD.2 SCMOD.0 ScmodSCMOD.3 SCMOD.2 SCMOD.0 Fx Oscillation Fxt Oscillation Oscillator CIRCUITSKS57C2308/P2308/C2316/P2316 KS57C2308/P2308/C2316/P2316OSCILLATOR Circuits Switching the CPU Clock Elapsed Machine Cycles During CPU Clock Switch Clock Output Mode Register Clmod Result of CLMOD.3 SettingCLMOD.1 CLMOD.0 Clock Source Frequency Clock Output Procedure Clock Output Circuit PMG2,EA + Programming TIP CPU Clock Output to the CLO PinCLMOD,A Interrupt Types and Corresponding Port Pins Interrupt Name InterruptsINT0, INT1, INT4 INTB, INTT0, Ints Power-Down Mode Release Vectored InterruptsSoftware-Generated Interrupts Multiple Interrupts Interrupt Execution Flowchart Interrupt Control Circuit Diagram Multiple Interrupts Two-Level Interrupt Handling Multi-Level Interrupt Handling Standard Interrupt Priorities Default Priority Interrupt Priority Register SettingsResult of IPR Bit Setting Interrupt Priority Register IPR IMOD0 IMOD0.3 IMOD0.1 IMOD0.0 IMOD1 IMOD1.0 External INTERRUPT0 and INTERRUPT1 Mode Registers INT0 Noise Filter Edge Clock SelectorINT1 IMOD0 IRQ0 IRQ1 Edge IMOD1 External Interrupt 2 Mode Register IMOD2 IMOD2 Register Bit SettingsEffect of IMOD2 Settings FB6H IMOD2.2 IMOD2.1 IMOD2.0 Circuit Diagram for INT2 and KS0-KS7 Pins Interrupt Flags IME IPR.2 IPR.1 IPR.0 Interrupt Request Flags IRQx Intb Btstz Irqb + Programming TIP Enabling the Intb and INT4 InterruptsIret INT4 Bitr IRQ4 POWER-DOWN Stop Idle CPU Idle Mode Timing Diagrams Timing When Idle Mode is Released by Reset Stop Mode Timing Diagrams Timing When Stop Mode is Released by Reset Keyclk Call MA2SUB P2,EAIMOD2,A SMB Bitr Irqw IRQ2 Bits IEW IE2 CLKS1 Call Watdis Port PIN Configuration for POWER-DOWN Recommended Connections for Unused Pins P3.1/LCDSYP3.0/LCDCK SEG0-SEG23 POWER-DOWN Timing for Oscillation Stabilization After Reset Hardware Register Values After Reset Program Status Word PSWData Memory RAM Clocks Basic Timer Timer/Counters 0Watchdog Timer LCD Driver/Controller KS57C2308/P2308/C2316/P2316 Port Mode Flags Pull-Up Resistor Mode Register PumodChannel Open-Drain Mode Register PNE 10 I/O Ports P6,EA PULL-UP Resistor Mode Register Pumod Port Mode Flags PM FlagsPumod ID Channel OPEN-DRAIN Mode Register PNE LMOD.7 and LMOD.6 Setting for Port 8 Output ControlLCD Output Segments Bit Output Pins PIN Addressing for Output Port SEG24 SEG251FAH SEG26 1FBH SEG27 Port 0 Circuit Diagram Port 0 Circuit Diagram Port 1 Circuit Diagram IMOD0 IMOD1 Port 2 Circuit Diagram Port 2 Circuit Diagram Port 3 and 6 Circuit Diagram Port 3 and 6 Circuit Diagram Port 4 and 5 Circuit Diagram Port 4 and 5 Circuit Diagram Port 7 Circuit Diagram Port 7 Circuit Diagram 10-12 KS57C2308/P2308/C2316/P2316 Timers and TIMER/COUNTERS Watchdog Timer Function Interval Timer FunctionOscillation Stabilization Interval Control Basic Timer Register Overview Type Description Size Addressing Reset Name ModeRAM Wdtcf Basic Timer Mode Register Bmod Basic Timer Mode Register Bmod OrganizationBasic Timer Input Clock Interval Time BMOD.3 Basic Timer Counter Bcnt Basic Timer Operation Sequence + Programming TIP Using the Basic Timer Watchdog Timer Mode Register Wdmod Watchdog Timer Counter WdcntWatchdog Timer Counter Clear Flag Wdtcf Bmod Reset Bits EMB SMB + Programming TIP Using the Watchdog TimerBMOD,A Main Bits Wdtcf BIT TIMER/COUNTER 0 TC0 TC0 Function Summary TC0 Component Summary TC0 Circuit Diagram TC0 Register Overview Type Description Size Enable Timer/Counter TC0 ENABLE/DISABLE ProcedureDisable Timer/Counter TC0 Programmable TIMER/COUNTER Function TC0 Operation Sequence TMOD0 Settings for TCL0 Edge Detection TC0 Event Counter FunctionTMOD0.5 TMOD0.4 TCL0 Edge Detection + Programming TIP TC0 Signal Output to the TCLO0 Pin TC0 Clock Frequency OutputTREF0,EA EA,#4CH TMOD0,EA Bits TOE0 TC0 Serial I/O Clock Generation TC0 External Input Signal DividerTREF0,EA EA,#0CH TMOD0,EA TC0 Mode Register TMOD0 TMOD0.6, TMOD0.5, and TMOD0.4 Bit Settings TMOD0.6 TMOD0.5 TMOD0.4Resulting Counter Source and Clock Frequency + Programming TIP Restarting TC0 Counting Operation TC0 Timing Diagram TC0 Counter Register TCNT0 TC0 Output Enable Flag TOE0 TC0 Reference Register TREF0MSB LSB TC0 Output Latch TOL0 + Programming TIP Setting a TC0 Timer Interval TREF0,EA Real-Time and Watch-Time Measurement Using a System or Subsystem Clock SourceClock Source Generation for LCD Controller Check Subsystem Clock Level Feature Timing Tests in High-Speed ModeBuzzer Output Frequency Generator Watch Timer Circuit Diagram Watch Timer Mode Register Wmod WMOD,EA Bits IEW + Programming TIP Using the Watch TimerClock Btstz Irqw LCD CONTROLLER/DRIVER Data BUS LCD Controller Driver LCD Circuit Diagram LCD Circuit Diagram LCD RAM Address Area LCON.0 and LMOD.3 Bit Settings LCD Control Register LconLCON.0 LMOD.3 COM0-COM3 SEG0-SEG31 P8.0-P8.7 LMOD.5 LMOD.4 LCD Mode Register LmodLMOD.3 LMOD.2 LMOD.1 LMOD.0 LCD Power Supply Static Mode Bias LCD Drive VoltageGND LCD Voltage Dividing Resistors Voltage Dividing Resistor Circuit Diagrams Common COM Signals LCD Common Signal Waveform Static LCD Common Signal Waveform at 1/2 Bias 1/2, 1/3 Duty LCD Common Signal Waveform at 1/3 Bias 1/3, 1/4 Duty Segment SEG Signals Select/No-Select Signals for LCD Static Display ModeSEG Select No-select Select/No-Select Signals for LCD 1/2 Bias Display Mode Select Non-select Select/No-Select Signals for LCD 1/3 Bias Display Mode 10. Select/No-select Bias Signals in 1/3 Bias Display Mode 11. LCD Signal Waveforms in Static Mode COM0 SEG11 SEG12 VLC0 VSS +VLCD 0 Vlcd 12. LCD Connection Example in Static Mode 13. LCD Signal Waveforms at 1/2 Duty, 1/2 Bias COM0 COM1 SEG9 14. LCD Connection Example at 1/2 Duty, 1/2 Bias 15. LCD Signal Waveforms at 1/3 Duty, 1/2 Bias COM0 COM1 COM2 SEG12 16. LCD Connection Example at 1/3 Duty, 1/2 Bias 17. LCD Signal Waveforms at 1/3 Duty, 1/3 Bias 18. LCD Connection Example at 1/3 Duty, 1/3 Bias 19. LCD Signal Waveforms at 1/4 Duty, 1/3 Bias COM0 COM1 COM2 COM3 SEG13 20. LCD Connection Example at 1/4 Duty, 1/3 Bias 12-24 Serial I/O Interface Serial I/O Operation Sequence Serial I/O Interface Circuit Diagram Serial I/O Mode Register Smod SMOD.0SMOD.1 SMOD.2 Serial I/O Timing Diagrams SIO Timing in Transmit/Receive Mode Serial I/O Buffer Register Sbuf SBUF,EA EA,#0EEH SMOD,EABitr EMB EA,TDATA SBUF,EA EA,#4FH SMOD,EA SBUF,EA EA,#8FH SMOD,EA Bits IES Ints PushXCH EA,SBUF Bits SMOD.3 SBUF,EA EA,#0FH SMOD,EA High Speed SIO Transmission 13-8 Standard Electrical Characteristics Stop Mode Characteristics and Timing WaveformsElectrical Data Miscellaneous Timing Waveforms Parameter Symbol Conditions Rating Units D.C. Electrical CharacteristicsParameter Symbol Conditions Min Typ Max Units Absolute Maximum Ratings Output low D.C. Electrical Characteristics Concluded Stop mode DD = 5 V ± 10% CPU = fx/4, Scmod = 0100B Main System Clock Oscillator Characteristics Parameter Symbol Condition Min Typ Max Units Subsystem Clock Oscillator CharacteristicsInput/Output Capacitance A.C. Electrical Characteristics Input Width Parameter Symbol Conditions Min Typ Max Unit Released by Reset 17/fx Time Released by interrupt Timing Waveforms A.C. Timing Measurement Points Except for XIN and Xtin TCL0 Timing 10. Serial Data Transfer Timing QFP-1420C Package Dimensions Mechanical Data 15-2 16 KS57P2308/P2316 OTP KS57P2308/KS57P2316 REG Operating Mode CharacteristicsTest 16-4 16-5 KS57P2308/P2316 OTPKS57C2308/P2308/C2316/P2316 16-7 16-8 16-9 16-10 Timing Waveforms 16-12 16-13 11. Serial Data Transfer Timing 12. OTP Programming Algorithm KS57P2308/P2316 OTP KS57C2308/P2308/C2316/P2316 16-16 Shine Sama AssemblerSASM57 HEX2ROM Smds Product Configuration SMDS2+ 17-2 TB572308A/16A Target Board Xtal MDS SMDS2/SMDS2+ Idle LED XTIStop LED Pin Connectors for TB572308A/16A DIP KS57 Series Mask ROM Order Form Page KS57 Series Request for Production AT Customer Risk Risk Order InformationCustomer Risk Order Agreement Order Quantity and Delivery SchedulePage KS57C2308 Mask Option Selection Form Attachment Check oneProm Customer Checksum Company Name Signature EngineerPage KS57C2316 Mask Option Selection Form + What is the purpose of this order? KS57 Series OTP Factory Writing Order Form 1/2Page KS57P2308 OTP Factory Writing Order Form 2/2 Device Number+ Are you going to continue ordering this device? If so, how much will you be ordering? PCSPage KS57P2316 OTP Factory Writing Order Form 2/2