diff options
| -rw-r--r-- | jedec.c | 8 |
1 files changed, 6 insertions, 2 deletions
@@ -89,7 +89,11 @@ int probe_jedec(struct flashchip *flash) *(volatile uint8_t *)(bios + 0x2AAA) = 0x55; myusec_delay(10); *(volatile uint8_t *)(bios + 0x5555) = 0x90; - myusec_delay(10); + /* Older chips may need up to 100 us to respond. The ATMEL 29C020 + * needs 10 ms according to the data sheet, but it has been tested + * to work reliably with 20 us. Allow a factor of 2 safety margin. + */ + myusec_delay(40); /* Read product ID */ id1 = *(volatile uint8_t *)bios; @@ -101,7 +105,7 @@ int probe_jedec(struct flashchip *flash) *(volatile uint8_t *)(bios + 0x2AAA) = 0x55; myusec_delay(10); *(volatile uint8_t *)(bios + 0x5555) = 0xF0; - myusec_delay(10); + myusec_delay(40); printf_debug("%s: id1 0x%x, id2 0x%x\n", __FUNCTION__, id1, id2); if (id1 == flash->manufacture_id && id2 == flash->model_id) |
