L9803 STMicroelectronics, L9803 Datasheet - Page 105

• 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
6.1
Table 15.
Inherent
Immediate
Short
Long
No Offset
Short
Long
Short
Long
Short
Long
Instruction Set
ST7 Addressing Modes
The ST7 Core features 17 different addressing modes which can be classified in 7 main
groups:
The ST7 Instruction set is designed to minimize the number of bytes required per
instruction: To do so, most of the addressing modes may be subdivided in two sub-modes
called long and short:
●
●
The ST7 Assembler optimize the use of long and short addressing modes.
ST7 Addressing Mode Overview:
Inherent
Immediate
Direct
Indexed
Indirect
Relative
Bit operation
Mode
Direct
Direct
Direct
Direct
Direct
Indirect
Indirect
Indirect
Indirect
Long addressing mode is more powerful because it can use the full 64Kbyte address
space, however it uses more bytes and more CPU cycles.
Short addressing mode is less powerful because it can generally only access page
zero (0000 - 00FFh range), but the instruction size is more compact, and faster. All
memory to memory instructions use short addressing modes only (CLR, CPL, NEG,
BSET, BRES, BTJT, BTJF, INC, DEC, RLC, RRC, SLL, SRL, SRA, SWAP)
Indexed
Indexed
Indexed
Indexed
Indexed
Addressing Mode
nop
ld A,#$55
ld A,$10
ld A,$1000
ld A,(X)
ld A,($10,X)
ld A,($1000,X)
ld A,[$10]
ld A,[$10.w]
ld A,([$10],X)
ld A,([$10.w],X)
Syntax
00..FF
0000..FFFF
00..FF
00..1FE
0000..FFFF
0000..FFFF
00..FF
0000..FFFF
00..1FE
Destination
nop
ld A,#$55
ld A,$55
ld A,($55,X)
ld A,([$55],X)
jrne loop
bset
00..FF
00..FF
00..FF
00..FF
byte,#5
Address
Pointer
Example
byte
word
byte
word
Pointer Size
(Hex.)
Instruction Set
+ 0
+ 1
+ 1
+ 2
+ 0
+ 1
+ 2
+ 2
+ 2
+ 2
+ 2
Length
(Bytes)
105/126