MOTOROLA
MC68341 USER’S MANUAL
4- 49
* Set up system protection register:
* Software watchdog disabled, double bus fault monitor disabled, bus
* monitor BERR after 128 clocks.
MOVE.B
#6,SYPCR+MODBASE
***************************************************************************
* Clock synthesizer control register:
* Switch from 8.3 to 16.7 MHZ
MOVE.W
#$7F80,SYNCR+MODBASE
X-bit doubles the default speed
***************************************************************************
* Module configuration register:
* When FREEZE is asserted, software watchdog and periodic interrupt timer
* are disabled, bus monitor is enabled. Show Cycles enabled, external
* arbitration enabled. Supervisor/user SIM registers unrestricted,
* Interrupt Arbitration at priority $F
MOVE.W
#$420F,MCR+MODBASE
***************************************************************************
* Set up address masks and base addresses for the first 4 chip selects:
LEA
CSAM0+MODBASE,A0
Point to CS0 addr. mask location.
MOVEQ
#8-1,D0
Set up loop counter for 2 regs * 4 CSx
LEA
CSAM0$,A1
Point to init table location.
LOOP
MOVE.L
(A1)+,(A0)+
Init. addr mask and base addr reg
DBRA
D0,LOOP
***************************************************************************
* Data table for chip select initialization
***************************************************************************
* CS0 - EPROM - 00060000-0007ffff, 3-wait states, 16-bit, write protect, NCS
CSAM0$
DC.L
$0001FFFD
CSBAR0$
DC.L
$0006000B
* CS1 - RAM - 00000000-0000ffff, fast termination, NCS
CSAM1$
DC.L
$0000FFFC
CSBAR1$
DC.L
$00000007
* CS2 - external device - 00FFE8xx, external termination, NCS
CSAM2$
DC.L
$000000F3
CSBAR2$
DC.L
$00FFE803
* CS3 - secondary memory - 00000000-0003ffff, 1-wait state, 8-bit, NCS
CSAM3$
DC.L
$0003FFF6
CSBAR3$
DC.L
$00000003
* CS4-8 unused. Reset invalidates these registers, so initialization
* is not specifically required
CS4$
DC.L
$0,$0
CS5$
DC.L
$0,$0
CS6$
DC.L
$0,$0
CS7$
DC.L
$0,$0
***************************************************************************
END
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Freescale Semiconductor, Inc.
For More Information On This Product,
Go to: www.freescale.com
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