8XC251SA, SB, SP, SQ USER’S MANUAL
C-6
Table C-7. Register File
Mnemonic
Address
R0 – R7
Four banks of 8 registers. Select bank 0-3 with bits
RS1:0 of PSW.
R8 – R31
R11 = Accumulator (ACC)
R10 = B Register.
R32 – R55
Reserved
R56 – R63
DR56 = the extended data pointer (DPXL, DPH, DPL).
DR60 = the extended stack pointer (SPH, SPL).
NOTE:
1.
The registers in the register file are normally accessed by mnemonic. Depending on its loca-
tion, a register can be addressed as a byte, word, and/or dword. See Figure 3-7 on page
3-12.
2.
The four banks of registers are implemented as the lowest bytes of on-chip RAM and are
always accessible via addresses 00:0000H–00:001FH.
3.
Special function registers ACC, B, DPXL, DPH, DPL, SPH, and SPL are located in the regis-
ter file and can be accessed as R11, R10, DR56, and DR60).
Summary of Contents for 8XC251SA
Page 2: ......
Page 3: ...May 1996 8XC251SA 8XC251SB 8XC251SP 8XC251SQ Embedded Microcontroller User s Manual...
Page 18: ......
Page 19: ...1 Guide to This Manual...
Page 20: ......
Page 30: ......
Page 31: ...2 Architectural Overview...
Page 32: ......
Page 41: ...3 Address Spaces...
Page 42: ......
Page 63: ...4 Device Configuration...
Page 64: ......
Page 81: ...5 Programming...
Page 82: ......
Page 102: ......
Page 103: ...6 Interrupt System...
Page 104: ......
Page 120: ......
Page 121: ...7 Input Output Ports...
Page 122: ......
Page 132: ......
Page 133: ...8 Timer Counters and Watchdog Timer...
Page 134: ......
Page 153: ...9 Programmable Counter Array...
Page 154: ......
Page 170: ......
Page 171: ...10 Serial I O Port...
Page 172: ......
Page 187: ...11 Minimum Hardware Setup...
Page 188: ......
Page 197: ...12 Special Operating Modes...
Page 198: ......
Page 206: ......
Page 207: ...13 External Memory Interface...
Page 208: ......
Page 239: ...14 Programming and Verifying Nonvolatile Memory...
Page 240: ......
Page 250: ......
Page 251: ...A Instruction Set Reference...
Page 252: ......
Page 390: ......
Page 391: ...B Signal Descriptions...
Page 392: ......
Page 400: ......
Page 401: ...C Registers...
Page 402: ......
Page 436: ......
Page 437: ...Glossary...
Page 438: ......
Page 446: ......
Page 447: ...Index...
Page 448: ......
Page 458: ......