L9803 STMicroelectronics, L9803 Datasheet - Page 111

• Manufacturer Part Number: L9803
• Description: Super Smart Power Motor Driver With 8-bit Mcu, Ram, Eeprom, Adc, Wdg, Timers, Pwm And H-bridge Driver
• Manufacturer: STMicroelectronics

L9803
6.2
The relative addressing mode consists of two sub-modes:
Relative (direct):
The offset is following the opcode.
Relative (indirect):
The offset is defined in memory, which address follows the opcode.
Instruction groups
The ST7 family devices use an Instruction Set consisting of 63 instructions. The instructions
may be subdivided into 13 main groups as illustrated in the following table:
Using a pre-byte
The instructions are described with one to four opcodes.
In order to extend the number of available opcodes for an 8-bit CPU (256 opcodes), three
different probate pockets are defined. These prebytes modify the meaning of the instruction
they precede.
The whole instruction becomes:
PC-2 End of previous instruction
PC-1 Prebyte
PC
PC+1 Additional word (0 to 2) according to the number of bytes required to compute the
These prebytes enable instruction in Y as well as indirect addressing modes to be
implemented. They precede the opcode of the instruction in X or the instruction using direct
addressing mode. The prebytes are:
Load and Transfer
Stack operation
Increment/Decrement
Compare and Tests
Logical operations
Bit Operation
Conditional Bit Test and Branch
Arithmetic operations
Shift and Rotates
Unconditional Jump or Call
Conditional Branch
Interruption management
Code Condition Flag modification
effective address
opcode
LD
PUSH
INC
CP
AND
BSET
BTJT
ADC
SLL
JRA
JRxx
TRAP
SIM
CLR
POP
DEC
TNZ
OR
BRES
BTJF
ADD
SRL
JRT
WFI
RIM
RSP
BCP
XOR
SUB
SRA
JRF
HALT
SCF
CPL
SBC
RLC
JP
IRET
RCF
NEG
MUL
RRC
CALL CALLR
SWAP
Instruction Set
SLA
NOP RET
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