mirror of
https://github.com/cc65/cc65.git
synced 2024-11-16 02:10:52 +00:00
60 lines
1.6 KiB
ArmAsm
60 lines
1.6 KiB
ArmAsm
;
|
|
; Marco van den Heuvel, 2018-04-09
|
|
;
|
|
|
|
; unsigned char __fastcall__ set_scpu_speed (unsigned char speed);
|
|
;
|
|
;/* Set the speed of the SuperCPU cartridge, using SPEED_SLOW will switch to
|
|
; * 1 Mhz mode, SPEED_20X or SPEED_FAST will switch to 20 Mhz mode.
|
|
; *
|
|
; * Note that any value lower than SPEED_20X will switch to 1 Mhz mode, and
|
|
; * any value higher or equal to SPEED_20X will switch to 20 Mhz mode.
|
|
; *
|
|
; * This function will return the actual speed the CPU is at after trying
|
|
; * to set the requested speed, if this is not the speed that was requested
|
|
; * then possibly the hardware speed switch prevented any software speed
|
|
; * switching.
|
|
; *
|
|
; * This function does not check for the presence of the SuperCPU cartridge,
|
|
; * make sure you use 'detect_scpu();' before using.
|
|
; */
|
|
|
|
; unsigned char get_scpu_speed (void);
|
|
;
|
|
;/* Get the speed of the SuperCPU cartridge.
|
|
; *
|
|
; * Possible return values:
|
|
; * SPEED_1X : 1 Mhz mode
|
|
; * SPEED_20X : 20 Mhz mode
|
|
; *
|
|
; * This function does not check for the presence of the SuperCPU cartridge,
|
|
; * make sure you use 'detect_scpu();' before using.
|
|
; */
|
|
|
|
.export _set_scpu_speed
|
|
.export _get_scpu_speed
|
|
|
|
.include "accelerator.inc"
|
|
|
|
_set_scpu_speed:
|
|
cmp #SPEED_20X
|
|
bcs high_speed
|
|
low_speed:
|
|
sta SuperCPU_Slow
|
|
jmp _get_scpu_speed
|
|
|
|
high_speed:
|
|
sta SuperCPU_Fast
|
|
|
|
_get_scpu_speed:
|
|
ldx #$00
|
|
lda SuperCPU_Speed_Mode
|
|
asl
|
|
asl
|
|
bcc is_fast_speed
|
|
lda #SPEED_1X
|
|
rts
|
|
is_fast_speed:
|
|
lda #SPEED_20X
|
|
rts
|