I don’t seem to be able to write to the JS28F128J3C flash chip on the CS-E9302 board. Even something simple like writing 0x90 to read back the device ID or 0x70 to read the status do not work.
I am booting to SDRAM via JTAG and making no other accesses to the flash chip. I can read it correctly; just can’t write to it.
What am I doing wrong?
More on this… I notice that when I’m reading from the flash, CSn6 is asserted coincident with RDn. However, when I do any write instruction to the flash chip, CDn6 is asserted, but WRn is not (nor is RDn, which is normal). Why would a write to CSn6 not assert the write strobe?
Do you mind post your initial script or explain how you initial ur board?
Got it. The bit labeled BLE (also referred to in the text as RBLE) in the SMCBR registers must be set to 1 or you can’t write to the corresponding chip select. This is not to be confused with WP which causes an abort on write. RBLE=0 just causes no write with no warning. Does anyone else find this confusing (or misleading)?