8XC251SA, SB, SP, SQ USER’S MANUAL
A-2
A.1
NOTATION FOR INSTRUCTION OPERANDS
Table A-1. Notation for Register Operands
Register Notation
MCS
®
251
Arch.
MCS 51
Arch.
@Ri
A memory location (00H–FFH) addressed indirectly via byte register
R0 or R1
✔
Rn
Byte register R0–R7 of the currently selected register bank
n
Byte register index: n = 0–7
r r r
Binary representation of n
✔
Rm
Byte register R0–R15 of the currently selected register file
Rmd
Destination register
Rms
Source register
m, md, ms
Byte register index: m, md, ms = 0–15
s s s s
Binary representation of m or md
S S S S
Binary representation of ms
✔
WRj
Word register WR0, WR2, ..., WR30 of the currently selected register
file
WRjd
Destination register
WRjs
Source register
@WRj
A memory location (00:0000H–00:FFFFH) addressed indirectly
through word register WR0–WR30
@WRj
Data RAM location (00:0000H–00:FFFFH) addressed indirectly
+dis16
through a word register (WR0–WR30) + displacement value, where
the displacement value is from 0 to 64 Kbytes.
j, jd, js
Word register index: j, jd, js = 0–30
t t t t
Binary representation of j or jd
T T T T
Binary representation of js
✔
DRk
Dword register DR0, DR4, ..., DR28, DR56, DR60 of the currently
selected register file
DRkd
Destination Register
DRks
Source Register
@DRk
A memory location (00:0000H–FF:FFFFH) addressed Indirectly
through dword register DR0–DR28, DR56, DR60
@DRk
Data RAM location (00:0000H–FF:FFFFH) addressed indirectly
+dis24
through a dword register (DR0–DR28, DR56, DR60) + displacement
value, where the displacement value is from 0 to 64 Kbytes
k, kd, ks
Dword register index: k, kd, ks = 0, 4, 8, ..., 28, 56, 60
u u u u
Binary representation of k or kd
U U U U
Binary representation of ks
✔
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...
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Page 30: ......
Page 31: ...2 Architectural Overview...
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Page 41: ...3 Address Spaces...
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Page 63: ...4 Device Configuration...
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Page 81: ...5 Programming...
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Page 102: ......
Page 103: ...6 Interrupt System...
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Page 121: ...7 Input Output Ports...
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Page 132: ......
Page 133: ...8 Timer Counters and Watchdog Timer...
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Page 153: ...9 Programmable Counter Array...
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Page 171: ...10 Serial I O Port...
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Page 187: ...11 Minimum Hardware Setup...
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Page 197: ...12 Special Operating Modes...
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Page 206: ......
Page 207: ...13 External Memory Interface...
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Page 239: ...14 Programming and Verifying Nonvolatile Memory...
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Page 250: ......
Page 251: ...A Instruction Set Reference...
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Page 390: ......
Page 391: ...B Signal Descriptions...
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Page 401: ...C Registers...
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Page 437: ...Glossary...
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Page 447: ...Index...
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