John Payson wrote: > By contrast, if one is using a PIC with built-in SPI hardware to help > with the EEPROM accesses (and even SPI hardware could help if data-in and > data-out were tied together) having a one-byte readahead could be quite > useful since 8 of the 9 clocks for each byte could be handled in hardware > while software was processing the previous byte. Hmmm. The original gist of it got lost somewhere...;) I want to bit-bang an *SPI* memory from an *SX*. I2C is nice&easy, but SPI is faster. I'll run the SX at full 50Mips. I want to get away from the hardware peripherals. If I manage to do that, future projects will be immune to lack of it ("but it only has one UART, snif, snif") I am looking at Ramtron's FRAM at the moment (thanks, Andy), because it can read and write at 2.1Mbits. The only disadvantage is the max memory size (4kbits) of these parts. > BTW, another suggestion for speeding up the interpreter: use four I2C > devices with a shared clock wire and seperate data wires. This would > allow 32 bits of data to be read much faster than with a single device. > The one caveat would be that all accesses (reads and writes) would be > 32 bits wide (for fastest access, each byte would be stored as two bits > on each device). This caveat aside, though, the much-improved data > speed should make that method pretty quick. It is definately a good idea. It could even be expanded further. The bottleneck of the project at the moment is the SPI RAM. It seems that it can be pretty pricey... > Name: WINMAIL.DAT > WINMAIL.DAT Type: unspecified type (application/octet-stream) > Encoding: x-uuencode Hey John, do you know about this little cyber turd dragging behind your mail? -- Friendly Regards /"\ \ / Tjaart van der Walt X ASCII RIBBON CAMPAIGN mailto:tjaart@wasp.co.za / \ AGAINST HTML MAIL |--------------------------------------------------| | Cellpoint Systems SA | | http://www.cellpt.com | |--------------------------------------------------| | http://www.wasp.co.za/~tjaart/index.html | |Voice: +27-(0)11-622-8686 Fax: +27-(0)11-622-8973| | WGS-84 : 26¡10.52'S 28¡06.19'E | |--------------------------------------------------|