Prius internal computer power

Considering that the average modern car has around 50 different microcontrollers it isn't so much a question of the power but how many additional microcontrollers did they add. Auto manufacturers are looking at trying to have one controller take over more functions to limit the number but typically these type of devices will have relatively little power compared to a personal computer. The main ECU on a prius is probably just a 32 bit Freescale MCU with under 1Mbyte RAM & ROM using an off board EEPROM for additional memory if needed.

I have personally built an ECU (fuel control only) for a car with a 20MHz, 256byte RAM, 8Kbyte ROM, PIC microcontroller and still had room left over (I did use closed loop control but did not try to implement every OBD-II sensor).

 

IIRC, some of the ECU's are NEC V850 based.
This was the CPU that was also found in nintendo's Virtual Boy.

 

Embedded applications don't really take much to operate and support.

There's no overlying fat OS to take care of nor fancy GUI interface for the user. Also, the hardware is usually purpose built, or designed for the application, rather than being a general purpose CPU and its associated neediness for ram and speed.

 

<div class='quotetop'>QUOTE(syclone @ Jun 17 2006, 11:51 PM) [snapback]272925[/snapback]</div>

For future Prius Computer searches, I did a "cut and paste" of an 11/17/05 Acronyms and Abbreviations posting of the Electronic Control Unit (ECU) section by member hdrygas that describes the following 14 (15 with Navigation) computer control units in the car:

1. HV ECU High Voltage ECU This is the brains of the HSD receiving and sending signals from all parts of the HSD turning driver request (shift, accelerator, break) into action by parts of the HSD system.

2. ECM Engine Module controls the ICE (spark, fuel injection, valve timing etc) delivering the proper amount of power to the system under direction of the HV ECU and informs HV ECU of ICE state.

3. Transmission ECU after receiving On signal from HV ECU monitors the Parking Switch (button) and when pressed it locks the hybrid trans axle and locks when brake is pressed and car is placed in D, R, N

4. Skid Control ECU Controls regenerative brake effect by MG2 and the hydraulic system to mimic a conventional hydraulic system as well as functions of Brake Assist, ABS (Antilock Brake System) and VSC (Vehicle Stability Control)

5. ECB ECU = Electronically Controlled Brake integrated into the Skid control ECU to calculate required brake force based on peddle effort and force.

6. EPS ECU = Electronic Power Steering ECU controls the power assist to steering column calculated from input from the Skid Control ECU and various sensors

7. Battery ECU monitors the SOC (State Of Charge) and battery temperature communicates with the HV ECU and controls the HV battery cooling fan.

8. Power Source Control ECU Controls the push button start system receives signals from switches and ECUs communicates to the HV ECU power on power off

9. Air Conditioning ECU calculates the compressor speed based on input from sensors using a nonlinear fuzzy logic system controls blower speed

10. Meter ECU Transmits vehicle speed signal, receives information if smart key is in vehicle and sound the warning sound in car on request of other ECUs (the source of the annoying beeps)

11. Body ECU receives door lock and unlock request and monitors if smart key is in vehicle transmits this to Smart ECU over a serial connection.

12. Transponder ECU Controls the HV immobilizer by recognizing the key ID code also works with Smart ECU in cars equipped with SKS. Transmits an HV stat authorization to the HV ECU

13. Smart ECU Checks ID code received from wireless transponders in the car and transmits the code to the Transponder ECU

14. Navigation ECU provides navigational features as well as Voice recognition and Bluetooth connection.

15. Gateway ECU provides communication between the 3 LANs (Local Area Network)