Cars · Diagnostics
Oki 80C154 Microcontroller Technical Reference
Technical overview of the Oki 80C154 microcontroller used in OBD0 MPFI ECUs, featuring 8051 compatibility and external EPROM requirements.
The Oki 80C154 is a microcontroller unit (MCU) utilized in OBD0 MPFI ECUs. It is characterized by the absence of internal code memory, necessitating the use of an external EPROM for operation.
Architecture Overview
The 80C154 is largely compatible with the standard 8051 instruction set architecture. Key features include:
- External Memory: Requires an external EPROM as it contains zero internal code memory.
- Timer Configuration: Includes a third timer, distinguishing it from standard 8051 implementations.
- Instruction Handling: The primary architectural deviation from a standard 8051 involves the handling of the A5 instruction.
Important
When performing diagnostics or modifications on ECUs utilizing the 80C154, ensure that external EPROM mapping is correctly verified, as the MCU relies entirely on this external storage for its instruction set.
Technical Specifications
| Feature | Specification |
|---|---|
| Architecture | 8051 Compatible |
| Internal Memory | 0 KB (External Required) |
| Timer Count | 3 |
| Primary Application | OBD0 MPFI ECUs |
Compatibility
This MCU is found in the following chassis platforms:
- DA: Acura Integra
- EF: Honda Civic / CRX