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NEC switch User Manual

Page 147

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CHAPTER 8 USB FUNCTION

User’s Manual U12978EJ3V0UD

147

8.8.2 Receive bank switching ID detection buffer operation

Figure 8-26. Flowchart of Receive Bank Switching ID Detection Buffer Operation

Y

Y

Y

01B

00B

N

Idle state

Idle state

2-bit store & shift

1-bit store & shift

Set buffer to 00H

Bit judgment enable

Set TOSTAT

Bit judgment mask

Sync1 detection

signal = 1?

EOP received?

Store bit ?

Set DASTAT

Set HSSTAT

11B

10B

TOSTAT:

Bit 0 of packet receive status register (RXSTAT)

DASTAT:

Bit 1 of packet receive status register (RXSTAT)

HSSTAT:

Bit 2 of packet receive status register (RXSTAT)