Register set
ST10F276E
hwbit
Bit that is set/cleared by hardware is written in bold
22.3
General purpose registers (GPRs)
The GPRs form the register bank that the CPU works with. This register bank may be
located anywhere within the internal RAM via the Context Pointer (CP). Due to the
addressing mechanism, GPR banks reside only within the internal RAM. All GPRs are bit-
addressable.
Table 65. General purpose registers (GPRs)
Physical
address
8-bit
address
Reset
value
Name
Description
R0
(CP) + 0
F0h
CPU general purpose (word) register R0
CPU general purpose (word) register R1
CPU general purpose (word) register R2
CPU general purpose (word) register R3
CPU general purpose (word) register R4
CPU general purpose (word) register R5
CPU general purpose (word) register R6
CPU general purpose (word) register R7
CPU general purpose (word) register R8
CPU general purpose (word) register R9
CPU general purpose (word) register R10
CPU general purpose (word) register R11
CPU general purpose (word) register R12
CPU general purpose (word) register R13
CPU general purpose (word) register R14
CPU general purpose (word) register R15
UUUUh
UUUUh
UUUUh
UUUUh
UUUUh
UUUUh
UUUUh
UUUUh
UUUUh
UUUUh
UUUUh
UUUUh
UUUUh
UUUUh
UUUUh
UUUUh
R1
(CP) + 2
F1h
F2h
F3h
F4h
F5h
F6h
F7h
F8h
F9h
FAh
FBh
FCh
FDh
FEh
FFh
R2
(CP) + 4
R3
(CP) + 6
R4
(CP) + 8
R5
(CP) + 10
(CP) + 12
(CP) + 14
(CP) + 16
(CP) + 18
(CP) + 20
(CP) + 22
(CP) + 24
(CP) + 26
(CP) + 28
(CP) + 30
R6
R7
R8
R9
R10
R11
R12
R13
R14
R15
The first eight GPRs (R7...R0) may also be accessed bytewise. Other than with SFRs,
writing to a GPR byte does not affect the other byte of the respective GPR. The respective
halves of the byte-accessible registers have special names:
Table 66. General purpose registers (GPRs) bytewise addressing
Physical
address
8-bit
address
Reset
value
Name
Description
RL0
(CP) + 0
(CP) + 1
(CP) + 2
(CP) + 3
F0h
CPU general purpose (byte) register RL0
CPU general purpose (byte) register RH0
CPU general purpose (byte) register RL1
CPU general purpose (byte) register RH1
UUh
UUh
UUh
UUh
RH0
RL1
RH1
F1h
F2h
F3h
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Doc ID 12303 Rev 3
STMICROELECTRONICS [ ST ]
