ST72C254G2M6 STMicroelectronics, ST72C254G2M6 Datasheet - Page 92

• Manufacturer Part Number: ST72C254G2M6
• Description: IC MCU 8BIT 8K FLASH SOIC-28
• Manufacturer: STMicroelectronics
• Series: ST7r

Specifications of ST72C254G2M6

• Core Processor: ST7
• Core Size: 8-Bit
• Speed: 16MHz
• Connectivity: I²C, SPI
• Peripherals: LVD, POR, PWM, WDT
• Number Of I /o: 22
• Program Memory Size: 8KB (8K x 8)
• Program Memory Type: FLASH
• Ram Size: 256 x 8
• Voltage - Supply (vcc/vdd): 3.2 V ~ 5.5 V
• Data Converters: A/D 6x8b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 28-SOIC (7.5mm Width)
• Controller Family/series: ST7
• No. Of I/o's: 22
• Ram Memory Size: 256Byte
• Cpu Speed: 8MHz
• No. Of Timers: 2
• Rohs Compliant: Yes
• Processor Series: ST72C2x
• Core: ST7
• Data Bus Width: 8 bit
• Data Ram Size: 256 B
• Interface Type: I2C, SPI
• Maximum Clock Frequency: 16 MHz
• Number Of Programmable I/os: 22
• Number Of Timers: 3 bit
• Operating Supply Voltage: 3.2 V to 5.5 V
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• Development Tools By Supplier: ST7MDT1-DVP2/US
• Minimum Operating Temperature: - 40 C
• On-chip Adc: 8 bit
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Eeprom Size: -
• Lead Free Status / Rohs Status: In Transition

ST72104Gx, ST72215Gx, ST72216Gx, ST72254Gx
ST7 ADDRESSING MODES (Cont’d)
12.1.6 Indirect Indexed (Short, Long)
This is a combination of indirect and short indexed
addressing modes. The operand is referenced by
its memory address, which is defined by the un-
signed addition of an index register value (X or Y)
with a pointer value located in memory. The point-
er address follows the opcode.
The indirect indexed addressing mode consists of
two sub-modes:
Indirect Indexed (Short)
The pointer address is a byte, the pointer size is a
byte, thus allowing 00 - 1FE addressing space,
and requires 1 byte after the opcode.
Indirect Indexed (Long)
The pointer address is a byte, the pointer size is a
word, thus allowing 64 Kbyte addressing space,
and requires 1 byte after the opcode.
Table 20. Instructions Supporting Direct,
Indexed,
Addressing Modes
92/141
Short Instructions Only
LD
CP
AND, OR, XOR
ADC, ADD, SUB, SBC
BCP
CLR
INC, DEC
TNZ
CPL, NEG
BSET, BRES
BTJT, BTJF
SLL, SRL, SRA, RLC,
RRC
Long and Short
Instructions
Indirect
and
Clear
Increment/Decrement
Test Negative or Zero
1 or 2 Complement
Bit Operations
Bit Test and Jump Opera-
tions
Shift and Rotate Operations
Load
Compare
Logical Operations
Arithmetic Addition/subtrac-
tion operations
Bit Compare
Indirect
Function
Function
Indexed
12.1.7 Relative Mode (Direct, Indirect)
This addressing mode is used to modify the PC
register value by adding an 8-bit signed offset to it.
The relative addressing mode consists of two sub-
modes:
Relative (Direct)
The offset follows the opcode.
Relative (Indirect)
The offset is defined in memory, of which the ad-
dress follows the opcode.
Available Relative Direct/
SWAP
CALL, JP
JRxx
CALLR
Indirect Instructions
Swap Nibbles
Call or Jump subroutine
Conditional Jump
Call Relative
Function