[N8VEM: 16370] w25x80 flash on parportprop for Zeta, also resistor tolerance

[Jim Strickland]

I've been gathering parts for my Zeta build, and I discovered, from a dead motherboard, a winbond w25x80 flash bios chip. It's an 8 pin, 8mbit part, and looking at the relative pinouts, it's almost the same, but expressed in different language. Datasheet here: http://www.winbond.com.tw/NR/rdonlyres/E1EAF68E-115A-4533-9384-FA31B9126F6B/0/W25X10_W25X20_W25X40_W25X80.pdf

Has anyone tried one of these things in place of the 24LC512 on the parportprop? It looks as though it should, at least, not go up in smoke - power and ground are in the same place.

Also, how critical are the 130 ohm resistors on the parportprop? (r18-20) I've inadvertently soldered 120s instead of 130s. They're within 10%. Do I need better than that?

-JRS

[Jim Strickland]

To answer my own question, my experiments with my rom burner suggest that no, the winbond chip neither reads nor writes properly when treated as a 24LC512.

[AG5AT]

Ok,
If you never have messed with Propellers, then this is a different animal.
The prop programs the chip. You must hook up to the programming interface
on the board serial or thru a prop plug which is really a usb to serial
device. The Propeller software will download the firmware to the Prop and
then it will write it to the prom. That is the only way.

Aug

Post by Jim Strickland
To answer my own question, my experiments with my rom burner suggest that
no, the winbond chip neither reads nor writes properly when treated as a
24LC512.

[Jim Strickland]

I knew the paraportprop could do that. I didn't know that it had to.
Thanks. The fact that, despite appearances, the winbond 25x80 is not pin
compatible with the 24LC512 and thus can't be used in the socket on the
parportprop board is the fact I was after in this case. When you load an
eeprom image that way, does the propeller just copy the whole image to the
eeprom, or does it run part of it and generate the eeprom image as some
subset of that data? I didn't count the bytes to see if the image is bigger
than 512k, which would invalidate my test.

Post by AG5AT
Ok,
If you never have messed with Propellers, then this is a different
animal. The prop programs the chip. You must hook up to the programming
interface on the board serial or thru a prop plug which is really a usb to
serial device. The Propeller software will download the firmware to the
Prop and then it will write it to the prom. That is the only way.
Aug

Post by Jim Strickland
To answer my own question, my experiments with my rom burner suggest that
no, the winbond chip neither reads nor writes properly when treated as a
24LC512.

[Sergey]

25LC512 has SPI interface while 24LC512 has I2C interface. They are not
compatible :-)

[Jim Strickland]

D'oh. Missed that. Thanks. -JRS

Post by Sergey
25LC512 has SPI interface while 24LC512 has I2C interface. They are not
compatible :-)
130 ohm vs. 120 ohm - not really critical.