DFU_DNLOAD request commands

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DocID017068 Rev 4

Figure 6. Download request: Host side

1. Operations needing System Reset are: Read Unprotect command and Write operations to the option

bytes.

2. After returning to the dfuDNBUSY state, the device executes the requested operation and performs a

system reset. The host may simply wait for the next enumeration or perform Get status again but the

device will not be able to respond, unless it fails to execute the requested operation.

Note:

Before issuing a Download request, the host has to check that the device is in a correct

state: dfuIDLE or dfuDNLOD-IDLE, and that there is no error reported in the status. If the

device is not in the required state/status, the host has to clear any error (DFU_CLRSTATUS

request) and get the status again until the device returns to the dfuIDLE state.