I was wanting to use a parallel flash memory chip with the picaxe 18X output pins connected to the address of the memory and be able to read the parallel output data directly from the memory data pins.
eg. If I had the letters of the alphabet stored in the memory at the first 26 locations as 8 bit ascii, could I for example by using the let pins = %xxxxxxxx command change the address on the memory and the corresponding character would appear on the data pins. Or do I also need to raise and lower the CE, OE or WE as a read cycle. The datasheet says the flash can be read like an eprom if CEand OE is low and WE is High the data for the address is output to the data pins. But it also says that addresses are latched on falling edge of CE or WE and data is Latched on rising edge of WE or CE. Is this only for commands and will array data read out continuously if CE WE OE are held in the appropriate state continuously while the address pins change as the picaxe sends new codes. I was wanting to use all the output pins of the picaxe as out to the memory address pins so no more pins left for the control if needed ??. The memory chip I was looking at is the Am29F010B by AMD Spansion, I think the Atmel Flash are similar ??. The same query goes for writing data to the memory, can I hold the control pins in the appropriate state and clock up through the addresses and as each address is set will the data I present to the data pins be stored in flash or do I need to raise and lower the control pins to create a write cycle for each address. I have a few of the memory chips, I don't mind blowing one to try it out but would be grateful someone could enlighten me or give me some confirmation on the way to go.......
eg. If I had the letters of the alphabet stored in the memory at the first 26 locations as 8 bit ascii, could I for example by using the let pins = %xxxxxxxx command change the address on the memory and the corresponding character would appear on the data pins. Or do I also need to raise and lower the CE, OE or WE as a read cycle. The datasheet says the flash can be read like an eprom if CEand OE is low and WE is High the data for the address is output to the data pins. But it also says that addresses are latched on falling edge of CE or WE and data is Latched on rising edge of WE or CE. Is this only for commands and will array data read out continuously if CE WE OE are held in the appropriate state continuously while the address pins change as the picaxe sends new codes. I was wanting to use all the output pins of the picaxe as out to the memory address pins so no more pins left for the control if needed ??. The memory chip I was looking at is the Am29F010B by AMD Spansion, I think the Atmel Flash are similar ??. The same query goes for writing data to the memory, can I hold the control pins in the appropriate state and clock up through the addresses and as each address is set will the data I present to the data pins be stored in flash or do I need to raise and lower the control pins to create a write cycle for each address. I have a few of the memory chips, I don't mind blowing one to try it out but would be grateful someone could enlighten me or give me some confirmation on the way to go.......