8.4 Acknowledge Polling
A Stop condition ends each command. Certain commands require an acknowledge polling sequence. Acknowledge polling consists of sending a Start condition followed by the command byte and determining if the device responds with an ACK. If the device is not ready for the command, it will not acknowledge, and the sequence must be repeated (Start condition, command byte, check for ACK). The ACK indicates that the operation has completed but gives no indication of the success or failure of the command.
- Read Commands: No ACK polling required.
- Write Commands: ACK polling required, except for encrypted write commands. Any command may be used.
- Set Commands: No ACK polling required.
- Verify Commands: ACK polling required with B2 or B6 commands only.
The following table lists the specific requirements for ACK polling and the maximum expected delay before the device will ACK, indicating readiness for the next command.
|
Command Description |
Command |
Addr 1 |
Addr 2 |
N |
ACK Polling CMD |
Delay | |
|---|---|---|---|---|---|---|---|
|
Write User Zone |
Normal |
$B0 |
Addr |
Addr |
N |
Required, any CMD |
5 ms |
|
Normal with Anti-Tearing Encrypted |
$B0 |
Addr |
Addr |
N |
Required, any CMD |
20 ms | |
|
$B0 |
Addr |
Addr |
N |
No, Send Checksum |
0 | ||
|
Encrypted with Anti-Tearing |
$B0 |
Addr |
Addr |
N |
No, Send Checksum |
0 | |
|
Random Read |
$B1 |
N/A |
N/A |
N/A |
Not Required | ||
|
Read User Zone |
$B2 |
Addr |
Addr |
N |
Not Required |
0 | |
|
System Write |
Write Config Zone |
$B4 |
$00 |
Addr |
N |
Required, any CMD |
5 ms |
|
Write Fuses |
$B4 |
$01 |
Fuse ID |
$00 |
Required, any CMD |
5 ms | |
|
Send Checksum |
$B4 |
$02 |
$00 |
$02 |
Required, any CMD |
5 ms | |
|
Send Checksum with Anti-Tearing |
$B4 |
$02 |
$00 |
$02 |
Required, any CMD |
20 ms | |
|
Set User Zone |
$B4 |
$03 |
Zone |
$00 |
Not Required |
0 | |
|
Write Config Zone with Anti-Tearing |
$B4 |
$08 |
Addr |
N |
Required, any CMD |
20 ms | |
|
Set User Zone with Anti-Tearing |
$B4 |
$0B |
Zone |
$00 |
Not Required |
0 | |
|
System Read |
Read Config Zone |
$B6 |
$00 |
Addr |
N |
Not Required |
0 |
|
Read Fuse Byte |
$B6 |
$01 |
$00 |
$01 |
Not Required |
0 | |
|
Read Checksum |
$B6 |
$02 |
$00 |
$02 |
Note Required |
0 | |
|
Verify Crypto |
Verify Authentication |
$B8 |
$0X |
$00 |
$10 |
Required; B2 or B6 only |
10 ms |
|
Verify Encryption |
$B8 |
$1X |
$00 |
$10 |
Required; B2 or B6 only |
10 ms | |
|
Verify Password |
Write Password |
$BA |
$0X |
$00 |
$03 |
Required; B2 or B6 only |
10 ms |
|
Read Password |
$BA |
$1X |
$00 |
$03 |
Required; B2 or B6 only |
10 ms | |