Bdisp SetDDRegisterB

Synopsis

Header: fxcg/display.h (Not yet in libfxcg)
Syscall index: 0x0194
Function signature: void Bdisp_SetDDRegisterB(int colorMode);

Used to enable/disable 8-color mode. Unlike Bdisp_EnableColor the results of this function are immediate.

Parameters

colorMode

• If nonzero disable 8-color mode.
• If zero enable 8-color mode.
  

Comments

Here is a disassembly of the function:

Bdisp_SetDDRegisterB:
		sts.l	pr, @-r15
		mov.l	#colorMode, r6
		extu.b	r4, r0
		tst	r0, r0
		bt/s	r0_zero
		mov.b	r4, @r6
		cmp/eq	#1, r0
		bt	r0_one
		bra	exit
		nop
! ---------------------------------------------------------------------------

r0_zero:
		bsr	Bdisp_DDRegisterSelect
		mov	#11, r4		! Select register 11
		mov	#0xFFFFFFB4, r2
		mov	#1, r6
		shll8	r2
		mov	#0, r4
		shll16	r2		! r2 = 0xB4000000
		mov.w	r6, @r2		! Enable 8 color mode
		synco
		bra	sub_8004CB96
		lds.l	@r15+, pr
! ---------------------------------------------------------------------------

r0_one:
		bsr	Bdisp_DDRegisterSelect
		mov	#11, r4		! Select register 11
		mov	#0xFFFFFFB4, r2
		mov	#0, r6
		shll8	r2
		mov	#1, r4
		shll16	r2		! r2 = 0xB4000000
		mov.w	r6, @r2		! Disable 8 color mode
		synco
		bra	sub_8004CB96
		lds.l	@r15+, pr
! ---------------------------------------------------------------------------

exit:
		lds.l	@r15+, pr
		rts
		nop
! End of function Bdisp_SetDDRegisterB