HydraFW binary NAND Flash mode guide

HydraFW binary NAND Flash mode guide

This guide is updated towards development firmware

Commands

Once the NAND mode has been selected, the following commands are available :

• 0b00000000 Return to main mode. Returns BBIO1
• 0b00000001 Displays the current mode. Returns FLA1
• 0b00000010 Puts the CE pin low. Returns 0x01
• 0b00000011 Puts the CE pin high. Returns 0x01
• 0b00000100 Write-then-read (see below)
• 0b00000110 Write command
• 0b00000111 Read byte
• 0b00001000 Wait for RB#
• 0b0001xxxx Write address

Command details

Write-then-read operation (0b00000100 - 0b00000101)

This command is used to send at most 4096 bytes and will read at most 4096 bytes of data. Format :

Byte 1           2          3          4          5         6        ...
|----------|----------|----------|----------|----------|----------|------...
 [command]    [Bytes to write]      [Bytes to read]       [Data to write

The bytes to read/write are in big-endian format. All data will be buffered before being sent to the Flash bus. Read data will also be buffered on the Hydrabus before being sent back to the user.

Write command (0b00000110)

This command will read the next byte, then send it to the flash with the CL line high. Hydrabus will send a 0x01 (acknowledge) once the operation is done.

Write address (0b0001xxxx)

In this mode, the last 4 bits of the command define the number of bytes to write (from 1 to 16) (Command 0b00010000 will send 1 byte). The same number of bytes will be read and sent to the flash with the AL line high. Hydrabus will send a 0x01 (acknowledge) once the operation is done.

Read byte (0b00000111)

This command will read a byte from the flash, send a 0x01 (acknowledge), then the read byte.

Wait for RB# (0b00001000)

This command will wait until thr RB# line is high, then send a 0x01 (acknowledge).