ST72124J2 STMicroelectronics, ST72124J2 Datasheet - Page 101

• Manufacturer Part Number: ST72124J2
• Description: 8-BIT MCU WITH SINGLE VOLTAGE FLASH MEMORY,ADC, 16-BIT TIMERS, SPI, SCI INTERFACES
• Manufacturer: STMicroelectronics

Specifications of ST72124J2

• Clock Sources: crystal/ceramic resonator oscillators or RC oscillators, external clock, backup Clock Security System
• 4 Power Saving Modes: Halt, Active-Halt, Wait and Slow
• Two 16-bit Timers With: 2 input captures (only one on timer A), 2 output compares (only one on timer A), External clock input on timer A, PWM and Pulse generator modes

15 INSTRUCTION SET
15.1 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
Table 20. ST7 Addressing Mode Overview
Note 1. At the time the instruction is executed, the Program Counter (PC) points to the instruction follow-
ing JRxx.
Addressing Mode
Inherent
Immediate
Direct
Indexed
Indirect
Relative
Bit operation
Inherent
Immediate
Short
Long
No Offset
Short
Long
Short
Long
Short
Long
Relative
Relative
Bit
Bit
Bit
Bit
Mode
Direct
Direct
Direct
Direct
Direct
Indirect
Indirect
Indirect
Indirect
Direct
Indirect
Direct
Indirect
Direct
Indirect
Indexed
Indexed
Indexed
Indexed
Indexed
Relative
Relative
Example
nop
ld A,#$55
ld A,$55
ld A,($55,X)
ld A,([$55],X)
jrne loop
bset
byte,#5
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)
jrne loop
jrne [$10]
bset $10,#7
bset [$10],#7
btjt $10,#7,skip
btjt [$10],#7,skip 00..FF
Syntax
00..FF
0000..FFFF
00..FF
00..1FE
0000..FFFF
00..FF
0000..FFFF
00..1FE
0000..FFFF
PC-128/PC+127
PC-128/PC+127
00..FF
00..FF
00..FF
Destination/
so, most of the addressing modes may be subdi-
vided in two sub-modes called long and short:
– Long addressing mode is more powerful be-
– Short addressing mode is less powerful because
The ST7 Assembler optimizes the use of long and
short addressing modes.
Source
cause it can use the full 64 Kbyte address space,
however it uses more bytes and more CPU cy-
cles.
it can generally only access page zero (0000h -
00FFh range), but the instruction size is more
compact, and faster. All memory to memory in-
structions use short addressing modes only
(CLR, CPL, NEG, BSET, BRES, BTJT, BTJF,
INC, DEC, RLC, RRC, SLL, SRL, SRA, SWAP)
ST72334J/N, ST72314J/N, ST72124J
1)
1)
00..FF
00..FF
00..FF
00..FF
00..FF
00..FF
00..FF
Address
Pointer
(Hex.)
byte
word
byte
word
byte
byte
byte
Pointer
(Hex.)
Size
+ 0
+ 1
+ 1
+ 2
+ 0 (with X register)
+ 1 (with Y register)
+ 1
+ 2
+ 2
+ 2
+ 2
+ 2
+ 1
+ 2
+ 1
+ 2
+ 2
+ 3
Length
(Bytes)
101/153