Intel 8XC196K Series User Manual page 607

Table of Contents

8XC196K x, J x , CA USER'S MANUAL

The window selection register (WSR) has two functions. One bit enables and disables the bus-hold

protocol. The remaining bits select windows. Windows map sections of RAM into the upper section of

the lower register file, in 32-, 64-, or 128-byte increments. PUSHA saves this register on the stack and

POPA restores it.

On the 87C196CA, 8XC196J x devices this bit is reserved; always write as zero.

Table C-24. WSR Settings and Direct Addresses for Windowable SFRs

CAN_BTIME0 (CA)

CAN_BTIME1 (CA)

Must be addressed as a word.

Hold Enable:

This bit enables and disables the bus-hold protocol (see Chapter 15,

"Enabling the Bus-hold Protocol (8XC196Kx Only)"). It has no effect on

1 = bus-hold protocol enabled

0 = bus-hold protocol disabled

Window Selection:

These bits specify the window size and window number:

6 5 4 3 2 1 0

1 x x x x x x 32-byte window; W5:0 = window number

0 1 x x x x x 64-byte window; W4:0 = window number

0 0 1 x x x x 128-byte window; W3:0 = window number

32-Byte Windows

(00E0–00FFH)

Reset State:

64-Byte Windows

(00C0–00FFH)

128-Byte Windows

(0080–00FFH)