Peripheral Control Module

The following table shows the location of the bits within HSSP control register 2. Both bits are set to one to ensure serial port 2’s pins default to normal “true” data operation following a reset of the SA-1100. Note that the HSSP and UART must be disabled (RXE=TXE=0) when changing the state of these bits. Also note that reads of reserved bits return zero and writes have no effect.

 

Address:

0h 9006 0028

 

 

HSCR2

 

Read/Write

 

Bit

23

22

21

20

19

18

17

16

 

 

 

 

 

 

 

 

 

 

 

 

 

Reserved

 

 

RXP

TXP

 

Reserved

 

 

 

 

 

 

 

 

 

 

 

 

Reset

0

0

0

0

1

1

0

0

Bit

Name

 

Description

 

 

 

17..16

Reserved.

 

 

 

18

TXP

Transmit pin polarity select.

 

 

0

– Data output from the HSSP, UART, or PPC is first inverted before being output to TXD2.

 

 

1

– Data output from the HSSP, UART, or PPC to TXD2 is true or non-inverted data.

 

 

 

19

RXP

Receive pin polarity select.

 

 

0

– Data input from RXD2 is first inverted before being used by the HSSP, UART, or PPC.

 

 

1

– Data input from RXD2 to the HSSP, UART, or PPC is true or non-inverted data.

 

 

 

23..20

Reserved.

 

 

 

 

11-118

SA-1100 Developer’s Manual

Page 268
Image 268
Intel SA-1100 manual 0h 9006, HSCR2, Rxp Txp