C166: ENABLING XBUS PERIPHERALS

Information in this article applies to:

• C166 Version 3.12
• C166 Version 4.05

QUESTION

How do I enable the XBUS peripherals on my C16x derivative?

ANSWER

This is done in the START167.A66 file. Copy this file from the \c166\lib directory to your project directory, edit it, and look for the section listed below:

;------------------------------------------------------------------------------
; Initialization for XPERCON register (available on some derivatives only)
;
; INIT_XPERCON: Init XPERCON register available on some devices
; --- Set INIT_XPERCON = 1 to initilize the XPERCON register
$SET (INIT_XPERCON = 0)
;
; --- XPERCON values
;
; V_CAN1: make CAN1 address range 0xEF00 .. 0xEFFF visible (XPERCON.0)
V_CAN1     EQU     1       ; 0 = CAN1 is not visible on the XBUS
;                          ; 1 = CAN1 is visible on the XBUS (default)
;
; V_CAN2: make CAN2 address range 0xEE00 .. 0xEEFF visible (XPERCON.1)
V_CAN2     EQU     0       ; 0 = CAN2 is not visible on the XBUS (default)
;                          ; 1 = CAN2 is visible on the XBUS
;
; V_XRAM2: make 2KB XRAM address range 0xE000 .. 0xE7FF visible (XPERCON.10)
V_XRAM2    EQU     1       ; 0 = 2KB XRAM is not visible on the XBUS
;                          ; 1 = 2KB XRAM is visible on the XBUS (default)
;
; V_XRAM6: make 6KB XRAM address range 0xC000 .. 0xD7FF visible (XPERCON.11)
V_XRAM6    EQU     0       ; 0 = 6KB XRAM is not visible on the XBUS (default)
;                          ; 1 = 6KB XRAM is visible on the XBUS
;
; V_XFLASH: make 4KB XFLASH address range 0x8000 .. 0x8FFF visible (XPERCON.14)
V_XFLASH   EQU     0       ; 0 = 4KB XFLASH is not visible on the XBUS (default)
;                          ; 1 = 4KB XFLASH is visible on the XBUS
;

Set INIT_XPERCON to a value of 1 and set the appropriate XRAM features to the desired states (0=off, 1=on).

FORUM THREADS

The following Discussion Forum threads may provide information related to this topic.

• C167CS - can't access XRAM @0xC000

Last Reviewed: Tuesday, June 20, 2000