ST7DALIF2 STMicroelectronics, ST7DALIF2 Datasheet - Page 124

• Manufacturer Part Number: ST7DALIF2
• Description: 8-BIT MCU WITH SINGLE VOLTAGE FLASH MEMORY, DATA EEPROM, ADC, TIMERS, SPI
• Manufacturer: STMicroelectronics

Specifications of ST7DALIF2

• 8 Kbytes Single Voltage Flash Program Memory With Read-out Protection, In-circuit Programming And In-application Programming (icp And Iap). 10k Write/erase Cycles Guaranteed, Data Retention: 20 years at 55°C.
• 256 Bytes Data Eeprom With Read-out Protection. 300k Write/erase Cycles Guaranteed, Data Retention: 20 years at 55°C.
• Clock Sources: Internal 1% RC oscillator, crystal/ceramic resonator or external clock
• Five Power Saving Modes: Halt, Active-Halt, Wait and Slow, Auto Wake Up From Halt

Instruction set
Note:
124/171
Using a prebyte
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 prebyte opcodes are defined. These prebytes modify the meaning of the instruction
they precede.
The whole instruction becomes:
PC-2
PC-1
PC
PC+1
These prebytes enable the 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:
PDY 90
PIX 92
PIY 91
Illegal Opcode Reset
In order to provide enhanced robustness to the device against unexpected behavior, a
system of illegal opcode detection is implemented. If a code to be executed does not
correspond to any opcode or prebyte value, a reset is generated. This, combined with the
Watchdog, allows the detection and recovery from an unexpected fault or interference.
A valid prebyte associated with a valid opcode forming an unauthorized combination does
not generate a reset.
Replace an X based instruction using immediate, direct, indexed, or inherent
End of previous instruction
Prebyte
Opcode
effective address
Replace an instruction using direct, direct bit, or direct relative addressing mode
to an instruction using the corresponding indirect addressing mode.
It also changes an instruction using X indexed addressing mode to an instruction
using indirect X indexed addressing mode.
Replace an instruction using X indirect indexed addressing mode by a Y one.
Additional word (0 to 2) according to the number of bytes required to compute the
addressing mode by a Y one.
ST7DALIF2