Typewriter User Manual

4- 38 MC68340 USER’S MANUAL MOTOROLA
4.4.3 SIM40 Example Configuration Code
The following code is an example configuration sequence for the SIM40 module.
***************************************************************************
* MC68340 basic SIM40 register initialization example code:
* This code is used to initialize the MC68340's internal SIM40 registers,
* providing basic functions for operation.
* It includes chip select programming for external devices.
* This code would be programmed beginning at offset $0 into ROM which is
* relocated to address $60000 by the initialization code.
* The SSP_VEC and RST_VEC vectors used to initialize the system stack
* pointer and initial PC, respectively, are located at offset $0 after
* reset.
***************************************************************************
* equates
***************************************************************************
SSP_INIT EQU $10000 Stack pointer initial value - top of RAM
MBAR EQU $0003FF00 Address of Module Base Address Reg.
MODBASE EQU $FFFFF000 Default Module Base address value
****************************************
* SIM40 register offsets from MBAR base address
MCR EQU $00
SYNCR EQU $04
SYPCR EQU $21
CSAM0 EQU $40
CSBAR0 EQU $44
CSAM1 EQU $48
CSBAR1 EQU $4c
CSAM2 EQU $50
CSBAR2 EQU $54
CSAM3 EQU $58
CSBAR3 EQU $5c
***************************************************************************
* Reset vectors
* These two vectors should be located at addresses $0 and $4 after a processor
* hardware reset.
***************************************************************************
ORG $60000
SSP_VEC DC.L SSP_INIT Supervisor stack pointer - initial value
RST_VEC DC.L INIT340 Reset vector pointing to initialization code
Frees
cale Semiconductor,
I
Freescale Semiconductor, Inc.
For More Information On This Product,
Go to: www.freescale.com
nc...