I am trying to read a microwire 93C66 EEprom which is connected to a Hitachi SH7055 MCU. The device is a complete automotive ECU. I need to be able to do this in circuit.
Currently I get an error when I try to read so I assume I need to hold the MCU in either reset or hardware standby mode.
The Eeprom is connected to the MCU as follows:
Pin1 - PIN193 PJ15/TI9F
Pin2 - PIN192 PJ14/TI9E
Pin3 - PIN191 PJ13/TI9D
Pin4 - PIN190 PJ12/TI9C
Can I just tie the HSTBY pin to GND or would I have to power the whole board?
What else would I have to do in order to read this EEprom in circuit?