W81281 View Datasheet(PDF) - Winbond

Part Name

Description

Manufacturer

W81281

USB Keyboard / Device Controller

Winbond 

W81281

Preliminary

7. PROGRAMMING NOTES:

The W81281 uses reserved bit of the Interrupt Priority Register IP.6 as a pre-decoding bit to implement a

alternative register and FIFO by External Data Memory Access of CPU core. Programming functions

described as below:

7.1 Control Registers Access:

Step 1: set IP.6 = 1

Step 2: access Control Register (by MOVX Instruction)

Step 3: set IP.6 = 0

7.2 Status Registers Access:

Step 1: set IP.6 = 1

Step 2 : set Read_Event = 1 in Control Register 3 ( by MOVX Instruction )

step 3 : access Status Registers ( by MOVX Instruction )

step 4 : set IP.6 = 0

7.3 FIFOs Access :

step 1 : set IP.6 = 1

step 2 : set EP0_RD_EN/EPX_WR_EN = 1 ( X : 0 - 4) (by MOVX Instruction )

step 3 : access FIFO by address 06H of MOVX Instruction

step 4 : set EP0_RD_EN/EPX_WR_EN = 0 ( X : 0 - 4) (by MOVX Instruction )

step 5 : set IP.6 = 0

7.4 Set Stall for Endpoint 0 - 4 :

step 1 : set IP.6 = 1

step 2 : set Set_Stall = 1 (by MOVX Instruction )

step 3 : set EP0_RD_EN/EPX_WR_EN = 1 ( X : 0 - 4) (by MOVX Instruction )

step 4 : set EP0_RD_EN/EPX_WR_EN = 0 ( X : 0 - 4) (by MOVX Instruction )

step 5 : set Set_Stall = 0 (by MOVX Instruction )

step 6 : set IP.6 = 0

Note : 1. EP0_RD_EN = 1 for OUT Transaction of EP0.

17

Publication Release Date: July 1999

Revision 0.60

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