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AN4440

USID modification

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5

USID modification

5.1

One HVDAC

5.1.1

Introduction

USID stands for Unique Slave Identifier. It is coded on 4 bits at the beginning of each RFFE

frame. Any HVDAC has a USID, by default 0111b, but can be reprogrammed. This is the

way to discriminate one slave from another and send instructions to the right device.

5.1.2

Sequence construction

USID reprogramming can be performed in 3 steps:

1.

Register 29 update

–

During this instruction, the USID, SELSID and product ID are checked and must

match the device

Figure 29. Register 29 update

2.

Register 30 update

–

During this instruction, the manufacturer ID is checked and must match the device

Figure 30. Register 30 update

3.

Register 31 update

–

During this instruction, the New USID is defined: here 0001b

Figure 31. Register 31 update