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Freescale Semiconductor MC68HC08KH12 manual Stack Pointer SP

Models: MC68HC08KH12

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6.4.3 Stack Pointer (SP)

The stack pointer is a 16-bit register that contains the address of the next location on the stack. During a reset, the stack pointer is preset to $00FF. The reset stack pointer (RSP) instruction also sets the least significant byte to $FF but does not affect the most significant byte. The stack pointer decrements as data is pushed onto the stack and increments as data is pulled from the stack.

In the stack pointer 8-bit offset and 16-bit offset addressing modes, the stack pointer can function as an index register to access data on the stack. The CPU uses the contents of the stack pointer to determine the conditional address of the operand.

	Bit															Bit
	15	14	13	12	11	10	9	8	7	6	5	4	3	2	1	0
Read:
Read:
Write:

Reset:	0	0	0	0	0	0	0	0	1	1	1	1	1	1	1	1

Figure 6-4. Stack Pointer (SP)

NOTE: The location of the stack is arbitrary and may be relocated anywhere in RAM. Moving the SP out of page zero ($0000 to $00FF) frees direct address (page zero) space. For correct operation, the stack pointer must point only to RAM locations.

MC68HC(7)08KH12 — Rev. 1.1	Advance Information

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Freescale Semiconductor MC68HC08KH12 manual Stack Pointer SP

Contents

MC68HC08KH12 Data Sheet Page Advance Information MC68HC708KH12 List of SectionsPage Table of Contents Random-Access Memory RAM System Integration Module SIM Clock Generator Module CGM Universal Serial Bus Module USB Monitor ROM MON O Ports Computer Operating Properly COP Keyboard Interrupt Module KBI Break Module Break Mechanical Specifications Page Title List of FiguresHDP1CR-HDP4CR Title Title Title List of TablesTitle General Description ContentsIntroduction FeaturesPage 1shows the structure of the MC68HC708KH12 MCU Block DiagramMCU Block Diagram 2Shows the 64-pin QFP assignments Pin AssignmentsPower Supply Bypassing SIM Module KBI and . Timer Interface Module TIM. Page Advance Information MC68HC708KH12 Memory MapMemory Map I/O Section Control, Status, and Data Registers Toie Control, Status, and Data Registers Pllie Keyff Rxdie $FF8D $FFFF 1is a list of vector locations Monitor ROMVector Addresses Page Functional Description Random-Access Memory RAMThis section describes the 384 bytes of RAM Page Read-Only Memory ROM Page Configuration Register Config = COP module disabled = COP module enabled Configuration Register ConfigCentral Processor Unit CPU CPU Registers FeaturesCPU Registers Index Register HX Stack Pointer SP Program Counter PC Condition Code Register CCR Page Arithmetic/Logic Unit ALU Page Advance Information MC68HC708KH12 System Integration Module SIMIntroduction SIM Block Diagram SIM I/O Register Summary Signal Name Conventions 1shows the internal signal names used in this sectionSIM Bus Clock Control and Generation Reset and System Initialization PIN Bit Set Timing External Reset TimingPower-On Reset COP reset is asynchronous to the bus clockComputer Operating Properly COP Reset POR RecoveryIllegal Address Reset Illegal Opcode ResetUniversal Serial Bus Reset SIM Counter Exception Control Interrupt Processing Hardware Interrupts Interrupt Entry11.Interrupt Recognition Example Interrupt Sources SWI Instruction12. Interrupt Status Register 1 INT1 Interrupt Status Register14. Interrupt Status Register 2 INT2 13. Interrupt Status Register 2 INT2Low-Power Modes 15. Wait Mode Entry Timing 16. Wait Recovery from Interrupt or Break 18. Stop Mode Entry Timing SIM Registers SIM Registers21. Reset Status Register RSR 22. Break Flag Control Register Bfcr Page Advance Information MC68HC708KH12 Clock Generator Module CGMIntroduction 1shows the structure of the CGM CGM Block Diagram Page FRDV = fRCLK/R Page 3MHz, or 1.5MHz respectively Choose P = 0, 1, 2, or 3 for a bus frequency of 12MHz, 6MHzCGM Numeric Example Page CGM External Connections I/O Signals Cgmvsel CGM Registers 101 CGM I/O Register Summary102 PLL Control Register Pctl103 104 PRE10 Programming105 PLL Multiplier Select Registers PmshpmslProgramming the PLL. RDS70 cannot be written when Initializes the register to $01 for a default divide valueRDS30 Reference Divider Select Bits Reference division factor R. See 8.4.3 PLL CircuitsSpecial Modes Interrupts107 108 Acquisition/Lock Time Specifications109 110 111 112 113 Universal Serial Bus Module USB114 Features115 Overview116 I/O Register Description of the HUB function117 HUB Control Register Summary118 Setup119 HUB Data Register Summary120 USB HUB Root Port Control Register Hrpcr121 USB HUB Downstream Port Control Registers122 123 USB SIE Timing Interrupt Register Sietir124 125 USB SIE Timing Status Register Sietsr126 127 USB HUB Address Register Haddr128 USB HUB Interrupt Register 0 HIR0129 USB HUB Control Register 0 HCR0130 131 USB HUB Control Register 1 HCR1132 10. USB HUB Status Register HSR133 134 I/O Register Description of the Embedded Device Function135 Embedded Device Control Register Summary136 Embedded Device Data Register SummaryDE1D0 13713. USB Embedded Device Interrupt Register 0 DIR0 12. USB Embedded Device Address Register Daddr139 140 14. USB Embedded Device Interrupt Register 1 DIR1141 15. USB Embedded Device Control Register 0 DCR0142 143 16. USB Embedded Device Control Register 1 DCR1144 17. USB Embedded Device Status Register DSR145 146 18. USB Embedded Device Control Register 2 DCR2147 19. USB Embedded Device Endpoint 0 Data Register UE0D0-UE0D7148 20. USB Embedded Device Endpoint 0 Data Register UE0D0-UE0D7149 Monitor ROM MON150 Features151 Monitor Mode Circuit152 Mode Selection153 Mode DifferencesSample Monitor Waveforms Monitor Data Format155 Break TransactionWrite Write Memory Command Read Read Memory Command156 Iwrite Indexed Write Command Iread Indexed Read Command157 RUN Run User Program Command Readsp Read Stack Pointer Command158 159 Monitor Baud Rate Selection160 161 Timer Interface Module TIM162 Introduction163 TIM Block Diagram164 TIM I/O Register Summary165 166 Unbuffered Output CompareBuffered Output Compare Registers of the linked pair alternately control the output167 168 Unbuffered PWM Signal Generation169 Buffered PWM Signal GenerationTIM status control register TSC, clear the TIM stop bit PWM Initialization170 171 Wait ModeTIM During Break Interrupts 11.8 I/O Signals172 173 11.9 I/O RegistersMinimum Tclk pulse width, Tclklmin or TCLKHMIN, is Maximum Tclk frequency is174 Resets the TIM counter Prescales the TIM counter clock175 Prescaler Selection176 TIM Counter Registers Tcnthtcntl177 TIM Counter Modulo Registers Tmodhtmodl178 TIM Channel Status and Control Registers TSC0TSC1179 See Table180 Mode, Edge, and Level Selection181 CHxMAX Latency182 TIM Channel Registers TCH0H/LTCH1H/L183 O Ports184 I/O Port Register Summary$0007 $0008 $0009 $000A $000B $001C $001D 185186 Port a3shows the port a I/O logic Data Direction Register a DdraPort a Pin Functions Port B188 6shows the port B I/O logic Data Direction Register B DdrbPort B Pin Functions Port C190 191 Data Direction Register C DdrcPort C Pin Functions Port D192 193 10. Port D Data Register PTD12shows the port D I/O logic 11. Data Direction Register D DdrdPort D Pin Functions Port E195 196 KBI15shows the port E I/O logic 14. Data Direction Register E Ddre198 Port E Pin FunctionsPTE0-PTE1 / PTE2-PTE3 199200 17. Optical Interface Voltage References201 18. Port E Optical Coupling Interface202 Port F3shows the port F I/O logic 20. Data Direction Register F DdrfPort F Pin Functions Port Options204 205 206 207 Computer Operating Properly COP1shows the structure of the COP module COP Block Diagram COP I/O Port Register Summary209 13.4 I/O Signals210 Configuration Register Config211 Monitor ModeCOP Control Register Copctl COP does not generate CPU interrupt requests212 COP Module During Break ModeIRQ module provides a non-maskable interrupt input External Interrupt IRQ213 214 Functional Description215 IRQ Module Block Diagram IRQ I/O Port Register Summary216 IRQ Status and Control Register Iscr IRQ Module During Break Interrupts217 218 219 Keyboard Interrupt Module KBI220 Introduction221 KBI I/O Register Summary222 Port-D Keyboard Interrupt Block Diagram223 224 225 Port-D Keyboard Status and Control Register226 Port-D Keyboard Interrupt Enable Register227 228 Port-E Keyboard Interrupt Block Diagram229 $FFED230 231 Port-E Keyboard Status and Control Register232 Port-E Keyboard Interrupt Enable Register233 234 Port-F Keyboard Interrupt Block Diagram235 236 237 Port-F Keyboard Status and Control Register238 Port-F Keyboard Interrupt Enable Register239 Stop ModePort-F Pull-up Enable Register Keyboard Module During Break Interrupts240 241 Break Module Break242 Features243 Break Module Block Diagram Break I/O Register Summary244 Break Module Registers245 Break Status and Control Register Brkscr246 Break Address Registers Brkh and Brkl247 Preliminary Electrical Specifications248 Absolute Maximum RatingsFunctional Operating Range Thermal Characteristics249 250 DC Electrical CharacteristicsControl Timing Oscillator Characteristics251 252 USB DC Electrical Characteristics253 USB Low Speed Source Electrical Characteristics254 USB High Speed Source Electrical Characteristics255 HUB Repeater Electrical CharacteristicsTImer Interface Module Characteristics USB Signaling Levels256 257 Clock Generation Module Characteristics258 Acquisition/Lock Time Specifications259 Mechanical Specifications260 Plastic Quad Flat Pack QFPPage How to Reach Us