Problems programming EEPROM

cbmeeks

I'm using proploader to program my Propeller. It's on COM4 and when I run it, it works OK. It's only when I try and burn the image into the EEPROM.

My assumption is that I have something wired incorrectly or maybe proploader doesn't work with my 128K EEPROM.

It's a 25AA1024. All of the voltages check out and I have plenty of decoupling caps.

I have the following wiring:

/HOLD = VCC
SI = SDA from Propeller
SCL = SCL
/WP = VCC
SO = Not connected
/CS = GND

Here is the message I get when I try and program:

Delivering second-stage loader
Downloading file to port COM4
2044 bytes sent
Verifying RAM
Programming EEPROM
EEPROM programming error: expected fffb4600, got fff68c00
ERROR: Download failed: -1

Any ideas?

Thanks

cbmeeks

UPDATE

I swapped the EEPROM out for a 24FC1025 and it worked. I can use that one for now but I am curious why the other doesn't work.

Thanks for any help.

Phil Pilgrim (PhiPi)

The Prop ROM code interfaces to the EEPROM using a 16-bit address field. The 24AA1024 requires a 24-bit address field. The 24FC1025 uses a 16-bit address field, with an additional block-access bit in the command byte, which the Prop sets to zero by default. That's why the latter is compatible with the Prop, and the former is not.

-Phil