1.17.2 Read Flash Command
This command will read the program flash and return the data read in the response packet. Because of the flash architecture, flash must always be read in modulus 4 byte lengths and the address must also be modulus 4 bytes or on PIC24/dsPIC33 instruction boundaries. The address of the memory range must reside entirely within the application space. If any of the requested data is outside of the application space, a status of 0xFE, Invalid Address, with no data will be returned.
|
Field Size |
Description |
Data Type |
Comments |
|---|---|---|---|
|
1 |
Command |
uint8_t |
Command (0x01) - Read Program Memory |
|
2 |
Length |
uint16_t |
Number of bytes to read. Length must be modulus 4 in length. |
|
4 |
Unlock Sequence |
uint32_t |
Unlock sequence for flash. Key for currently supported parts is 0x00AA0055 |
|
4 |
Address |
uint32_t |
Address of the first memory location to read. Address must modulus 4 bytes. |
Read Command Response Format
|
Field Size |
Description |
Data Type |
Comments |
|---|---|---|---|
|
1 |
Command |
uint8_t |
Command (0x01) - Read Program Memory |
|
2 |
Length |
uint16_t |
Number of bytes to read. |
|
4 |
Unlock Sequence |
uint32_t |
Unlock sequence for flash. Key for currently supported parts is 0x00AA0055 |
|
4 |
Address |
uint32_t |
Address of the first memory location to read. Must be modulus of 4 bytes. |
|
1 |
Status |
uint8_t |
Status of Command
|
Command Example Sequence
Read 8 bytes of data (0x01,0x02,0x03,0x04,0x05,0x06,0x07,0x08) starting at address 0x00001878. All values in Hex
Example command to the device
|
Field Size |
Description |
Data Type |
Value |
|---|---|---|---|
|
1 |
Command |
uint8_t |
0x01 |
|
2 |
Length |
uint16_t |
0x0008 |
|
4 |
Unlock Sequence |
uint32_t |
0x00AA0055 |
|
4 |
Address |
uint32_t |
0x00001878 |
Example as viewed on bus: 0x01, 0x08, 0x00, 0x55, 0x00, 0xAA, 0x00, 0x78, 0x18, 0x00, 0x00
Response Example Response Sequence
Example response from the device
|
Field Size |
Description |
Data Type |
Value |
|---|---|---|---|
|
1 |
Command |
uint8_t |
0x01 |
|
2 |
Length |
uint16_t |
0x0008 |
|
4 |
Unlock Sequence |
uint32_t |
0x00AA0055 |
|
4 |
Address |
uint32_t |
0x00001878 |
|
1 |
Status |
uint8_t |
0x01 |
|
8(for this example) |
Read Data from device |
uint8_t |
0x01,0x02,0x03,0x04,0x05,0x06,0x07,0x08 |
Example as viewed on bus: 0x01, 0x08, 0x00, 0x55, 0x00, 0xAA, 0x00, 0x78, 0x18, 0x00, 0x00, 0x01, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08