Flat Panel Television User Manual
Table Of Contents
- TOC
- 01-Overview
- 02-Address Space
- 03-Addressing Modes
- 04-Control Registers
- 05-Interrupt Structure
- 06-Instruction Set
- 07-Clock and Power Circuits
- 08-RESET
- 09-IO PORTS
- 10-BASIC TIMER and TIMER 0
- 11-Timer1
- 12-CounterA
- 13-Timer2
- 14-EMBEDDED Flash Memory Interface
- 15-Low Voltagge Detector
- 16-Electrical Data
- 17-Mechanical Data
- 18-Flash MCU
- 19-Development Tool
- TOC.pdf

INSTRUCTION SET S3F80P5_UM_ REV1.00
EI — Enable Interrupts
EI
Operation: SYM (0) ← 1
An EI instruction sets bit zero of the system mode register, SYM.0 to "1". This allows interrupts to
be serviced as they occur (assuming they have highest priority). If an interrupt's pending bit was
set while interrupt processing was disabled (by executing a DI instruction), it will be serviced
when you execute the EI instruction.
Flags: No flags are affected.
Format:
Bytes Cycles Opcode
(Hex)
opc
1 4 9F
Example: Given: SYM = 00H:
EI
If the SYM register contains the value 00H, that is, if interrupts are currently disabled, the
statement "EI" sets the SYM register to 01H, enabling all interrupts. (SYM.0 is the enable bit for
global interrupt processing.)
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