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NEC PD754144, PD754244 70 , 4.6 Accumulator, 4.7 Stack Pointer (SP) and Stack Bank Select Register (SBS)

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CHAPTER 4 INTERNAL CPU FUNCTION

70 User’s Manual U10676EJ3V0UM

4.6 Accumulator

With the

µ

PD754244, the A register or XA register pair functions as an accumulator. The A register plays a central

role in 4-bit data processing, while the XA register pair is used for 8-bit data processing.

When a bit manipulation instruction is used, the carry flag (CY) is used as a bit accumulator.

Figure 4-7. Accumulator

CY Bit accumulator

A 4-bit accumulator

A 8-bit accumulatorX

4.7 Stack Pointer (SP) and Stack Bank Select Register (SBS)

The

µ

PD754244 uses a static RAM as the stack memory (LIFO). The stack pointer (SP) is an 8-bit register that

holds information on the first address of the stack area.

The stack area consists of addresses 000H to 07FH of memory bank 0. A memory bank is specified by 2-bit SBS

(refer to Table 4-2).

Table 4-2. Stack Area Selected by SBS

SBS

SBS1 SBS2

0 0 Memory bank 0

Other than above, setting prohibited

The value of SP is decremented before data is written (saved) to the stack area, and is incremented after data

has been read (restored) from the stack memory.

The data saved or restored to or from the stack are as shown in Figures 4-9 to 4-12.

The initial values of SP and SBS are respectively set by an 8-bit memory manipulation instruction and 4-bit memory

manipulation instruction, to determine the stack area. The values of SP and SBS can also be read.

Stack Area

- - - - - -

Contents

Main Users Manual PD754144, 754244 Page NOTES FOR CMOS DEVICES Page Regional Information components, host computers, power plugs, AC supply voltages, and so forth) NEC Electronics America, Inc. (U.S.) NEC Electronics Hong Kong Ltd. NEC Electronics Shanghai, Ltd. Page INTRODUCTION Page Page Page Page Page LIST OF FIGURES (1/3) 14 LIST OF FIGURES (2/3) Page 16 LIST OF TABLES CHAPTER 1 GENERAL 18 1.1 Functional Outline 1.2 Ordering Information Part Number Package PD754141GS--BA5 20-pin plastic SOP (7.62 mm (300)) PD754141GS--GJG 20-pin plastic SSOP (7.62 mm (300)) PD754244GS--BA5 20-pin plastic SOP (7.62 mm (300)) 20 1.4 Block Diagram CHAPTER 1 GENERAL 1.5 Pin Configuration (Top View) Pin configuration of IC: Internally Connected (Directly connect to VDD.) PD754144 20-pin plastic SOP (7.62 mm (300)) PD754144GS--BA5 20-pin plastic SSOP (7.62 mm (300)) Pin configuration of PD754244 20-pin plastic SOP (7.62 mm (300)) IC: Internally Connected (Directly connect to VDD.) PD754244GS--BA5 20-pin plastic SSOP (7.62 mm (300)) PD754244GS--GJG Page 24 CHAPTER 2 PIN FUNCTIONS 2.1 Pin Functions of PD754244 Table 2-1. Pin Functions of Digital I/O Ports Table 2-2. Functions of Non-Port Pins Note Circled characters indicate Schmitt triggered input. 26 2.2 Description of Pin Functions Page PD754244 Page CHAPTER 2 PIN FUNCTIONS 30 2.3 Pin I/O Circuits The following diagrams show the I/O circuits of the pins of the PD754244. Note that in these diagrams the I/ O circuits have been slightly simplified. 2.4 Processing of Unused Pins Table 2-3. Recommended Connection of Unused Pins 32 CHAPTER 3 FEATURES OF ARCHITECTURE AND MEMORY MAP 3.1 Bank Configuration of Data Memory and Addressing Modes Page Page Figure 3-2. Data Memory Configuration and Addressing Range for Each Addressing Mode Page Page Page Figure 3-3. Updating Address of Static RAM Page Page Page Page Page 3.2 Bank Configuration of General-Purpose Registers Page Page Figure 3-5. Configuration of General-Purpose Registers (4-Bit Processing) Figure 3-6. Configuration of General-Purpose Registers (8-Bit Processing) 50 3.3 Memory-Mapped I/O Page Page Figure 3-7. PD754244 I/O Map (2/8) Figure 3-7. PD754244 I/O Map (3/8) Figure 3-7. PD754244 I/O Map (4/8) Figure 3-7. PD754244 I/O Map (5/8) Figure 3-7. PD754244 I/O Map (6/8) Note These are not registered as reserved words. Figure 3-7. PD754244 I/O Map (7/8) Figure 3-7. PD754244 I/O Map (8/8) 60 CHAPTER 4 INTERNAL CPU FUNCTION 4.1 Function to Select MkI and MkII Modes Page 62 4.2 Program Counter (PC) 12 bits 4.3 Program Memory (ROM) 4096 8 bits CHAPTER 4 INTERNAL CPU FUNCTION Figure 4-3. Program Memory Map 4.4 Data Memory (RAM) ... 128 words 4 bits Page Figure 4-4. Data Memory Map Page 4.5 General-Purpose Registers ... 8 4 bits 4 banks . 70 4.6 Accumulator 4.7 Stack Pointer (SP) and Stack Bank Select Register (SBS) Page Figure 4-9. Data Saved to Stack Memory (MkI Mode) Figure 4-10. Data Restored from Stack Memory (MkI Mode) Figure 4-11. Data Saved to Stack Memory (MkII Mode) Figure 4-12. Data Restored from Stack Memory (MkII Mode) Note The contents of PSW other than MBE and RBE are not saved or restored. Remark *: Undefined 74 4.8 Program Status Word (PSW) ... 8 Bits Page 76 Page 78 4.9 Bank Select Register (BS) Page 80 CHAPTER 5 EEPROM 5.1 EEPROM Configuration 5.2 EEPROM Features 5.3 EEPROM Write Control Register (EWC) 82 5.4 Interrupt Related to EEPROM Control 5.5 EEPROM Manipulation Method Page Page Page 5.6 Cautions on EEPROM Writing 88 CHAPTER 6 PERIPHERAL HARDWARE FUNCTION 6.1 Digital I/O Ports Page Figure 6-2. P3n Configuration (n = 0 to 2) MPX Internal bus Figure 6-3. P33 Configuration MPX Figure 6-4. P60 Configuration Figure 6-5. P61 Configuration Figure 6-6. P62 Configuration Figure 6-7. P63 Configuration Figure 6-8. P7n Configuration (n = 0 to 3) Figure 6-9. P80 Configuration Page Page Page Table 6-2. I/O Pin Manipulation Instructions Page Table 6-3. Operation When I/O Port Is Manipulated Remark <1> : Indicates two addressing modes: PORTn, bit and PORTn.@L. Page 0 1 2 (b) When data is loaded by 2-machine-cycle instruction (c) When data is latched by 1-machine-cycle instruction Instruction execution Manipulation instruction Output latch (output pin) Figure 6-13. ON Timing of Internal Pull-up Resistor Connected via Software 6.2 Clock Generator PD754144 (RC oscillation) Internal bus Figure 6-14. Block Diagram of Clock Generator (2/2) (b) PD754244 Crystal/Ceramic Oscillation Internal bus Page 106 Figure 6-15. Format of Processor Clock Control Register Remark fCC and fX: System clock oscillation frequency Page PD754144 PD754244 PD754144 PD754244 Page PD754144 PD754144 PD754244 PD754244 Page Page 114 6.3 Basic Interval Timer/Watchdog Timer Page Figure 6-21. Format of Basic Interval Timer Mode Register Note In the s at 1.0 MHz). PD754144, wait time is always fixed to 29/fCC (512 PD754244 only, wait time is selectable when standby mode is released. In the Page Page Page Example To use the PD754144, it is 32.8 ms at fCC = 1.0 MHz. Note It is 7.81 ms when the (After that, set bit 3 of BTM to 1 every 5.46 ms.) PD754244 is operating at fX = 4.19 MHz. In the case of the Page 122 6.4 Timer Counter Figure 6-23. Block Diagram of Timer Counter (Channel 0) Caution Be sure to clear bits 1 and 0 to 0 when setting data to TM0. Figure 6-24. Block Diagram of Timer Counter (Channel 1) Figure 6-25. Block Diagram of Timer Counter (Channel 2) Caution Be sure to clear bit 7 to 0 when setting data to TC2. Page Figure 6-26. Format of Timer Counter Mode Register (Channel 0) Figure 6-27. Format of Timer Counter Mode Register (Channel 1) (1/2) Page Figure 6-28. Format of Timer Counter Mode Register (Channel 2) (1/2) Figure 6-28. Format of Timer Counter Mode Register (Channel 2) (2/2) Page Page Page Figure 6-31. Setting of Timer Counter Mode Register (1/3) (a) Timer counter (channel 0) Note Be sure to clear bits 0 and 1 to 0 when setting data to TM0. Figure 6-31. Setting of Timer Counter Mode Register (2/3) (b) Timer counter (channel 1) Figure 6-31. Setting of Timer Counter Mode Register (3/3) (c) Timer counter (channel 2) Page Page (b) PD754244: at 4.19 MHz 8-bit timer counter (channel 0) 8-bit timer counter (channel 1) PD754144: at 1.0 MHz 8-bit timer counter (channel 0) 8-bit timer counter (channel 1) Page Figure 6-34. Configuration When Timer Counter Operates Figure 6-35. Count Operation Timing Remark m: Set value of timer counter modulo register n : 0 to 2 Page Page Figure 6-36. Setting of Timer Counter Mode Register Page Page Figure 6-38. PWM Pulse Generator Operating Configuration 012 i11012 k1k0123 Count pulse (CP) Timer counter count register (T2) TOUT F/F Set Timer start command Page Page Figure 6-40. Setting of Timer Counter Mode Registers Page Page Page Page Figure 6-42. Configuration When Timer Counter Operates Figure 6-43. Timing of Count Operation Page Page Figure 6-44. Setting of Timer Counter Mode Register (n = 1, 2) Page Page Page Figure 6-47. Configuration in Carrier Generator Mode Page Page Page Page Page Page Page Page Page Page Page Page Page Page 180 6.5 Programmable Threshold Port (Analog Input Port) Figure 6-49. Block Diagram of Programmable Threshold Port Page Page 184 6.6 Bit Sequential Buffer ... 16 Bits Page 186 CHAPTER 7 INTERRUPT AND TEST FUNCTIONS 7.1 Configuration of Interrupt Controller Figure 7-1. Block Diagram of Interrupt Controller Selector 188 7.2 Types of Interrupt Sources and Vector Table The Page 190 7.3 Hardware Controlling Interrupt Function Page Figure 7-3. Interrupt Priority Select Register Page Figure 7-4. Configuration of INT0 Remark tSMP = tCY or 64/fX Figure 7-6. Format of INT0 Edge Detection Mode Register (IM0) Page 7.4 Interrupt Sequence 198 7.5 Nesting Control of Interrupts Page 200 7.6 Servicing of Interrupts Sharing Vector Address Page 202 7.7 Machine Cycles Until Interrupt Servicing Page 204 7.8 Effective Usage of Interrupts 7.9 Application of Interrupt (1) Enabling or disabling interrupt Page Page (4) Executing pending interrupt - interrupt input while interrupts are disabled - (5) Executing pending interrupt - two interrupts with lower priority occur simultaneously - Page Page 212 7.10 Test Function Figure 7-10. Block Diagram of KR4 to KR7 Page CHAPTER 8 STANDBY FUNCTION 216 8.1 Settings and Operating Statuses of Standby Mode Table 8-1. Operating Statuses in Standby Mode Page 218 8.2 Releasing Standby Mode Page Page Page 222 8.3 Operation After Release of Standby Mode 8.4 Application of Standby Mode Page Page Page Page CHAPTER 9 RESET FUNCTION 9.1 Configuration and Operation of Reset Function Internal bus Page Page Page 9.2 Watchdog Flag (WDF), Key Return Flag (KRF) CHAPTER 9 RESET FUNCTION Figure 9-4. KRF Operation in Generating Each Signal CHAPTER 10 MASK OPTIONS 10.1 Pin Mask Options 10.2 Oscillation Stabilization Wait Time Mask Option 234 CHAPTER 11 INSTRUCTION SET 11.1 Unique Instructions Page Page 11.2 Instruction Set and Operation Page Page Page Page Page Note Set 0 to the B register. Page PCDE 2 3 Page Page 248 11.3 Opcode of Each Instruction Page Page Page Page Page 254 11.4 Instruction Function and Application MOV A, #n4 MOV reg1, #n4 MOV XA, #n8 MOV HL, #n8 MOV rp2, #n8 MOV A, @HL MOV A, @HL+ MOV A, @HL MOV A, @rpa1 MOV XA, @HL MOV @HL, A MOV @HL, XA MOV A, mem MOV XA, mem MOV mem, A MOV mem, XA MOV A, reg MOV XA, rp MOV reg1, A XCH A, @HL XCH A, @HL+ XCH A, @HL XCH A, @rpa1 XCH XA, @HL XCH A, mem XCH XA, mem XCH A, reg1 XCH XA, rp MOV XA, @PCDE Page MOVT XA, @PCXA MOVT XA, @BCDE MOVT XA, @BCXA Page ADDS A, #n4 ADDS XA, #n8 ADDS A, @HL ADDS XA, rp ADDS rp1, XA ADDC A, @HL ADDC XA, rp ADDC rp1, XA SUBS A, @HL SUBS XA, rp SUBS rp1, XA SUBC A, @HL SUBC XA, rp SUBC rp1, XA AND A, #n4 AND A, @HL AND XA, rp AND rp1, XA OR A, #n4 OR A, @HL OR XA, rp OR rp1, XA XOR A, #n4 Page 11.4.5 Accumulator manipulation instructions RORC A NOT A Page Page Page Page Page Page BR addr BR addr1 BRA !addr1 BR !addr BR $addr BR $addr1 BRCB !caddr BR PCDE BR PCXA BR BCDE BR BCXA TBR addr CALLA !addr1 CALL !addr CALLF !faddr TCALL !addr RET RETS RETI PUSH rp PUSH BS POP rp POP BS EI EI IE DI DI IE IN A, PORTn OUT PORTn, A Page SEL RBn SEL MBn GETI taddr Page Page APPENDIX A DEVELOPMENT TOOLS The following development tools are available to support development of systems using the PD754244. The following table shows the system configuration of the in-circuit emulators. Page Development Tool Configuration APPENDIX B ORDERING MASK ROM 298 APPENDIX C INSTRUCTION INDEX C.1 Instruction Index (By Function) Page Page C.2 Instruction Index (Alphabetical Order) Page Page 304 APPENDIX D HARDWARE INDEX Page 306 APPENDIX E REVISION HISTORY