HT66FV1x0 Integrated Audio Amplifier Application Guideline
AN0486EN V1.10
12 / 16
June 8, 2021
Power Off
Ramp Down
SPI Off
(pin PC7/SCSAB
→
0)
Off
SPI Off
clear SPIAEN
SPIAEN
→
0
clear SAMLS, SACSEN
SPIAC1
→
0x00
Disable SPI Pin
PCS1
→
0x00
Disable VDDIO
PBS0[1:0]
→
00B
Return
The following provides the demo codes for the ramp up and ramp down software flows, which aim
to avoid pop noise when switching on/off the DAC and audio power amplifier. Demo code settings
are as follows (f
SYS
=8MHz)
.
(1)
Power On Sequence settings using ASM language
MAIN_START:
CALL SPI_ON
CALL RAMP_UP
(2)
SPI On settings using ASM language
SPI_ON:
; enable VDDIO
MOV A,PBS0
OR
A,03H
MOV PBS0,A
; enable SPI pins
MOV A,01010101B
MOV PCS1,A
; set SAMLS, SACSEN
CLR SPIAC0
MOV A, 0CH
MOV SPIAC1, A
; set SPIAEN
SET SPIAEN
RET
(3)
Ramp Up settings using ASM language
RAMPUP:
MOV A,00H
MOV PLADL,A
; initialise DAC 16-bit data
MOV PLADH,A
SET DAEN
; enable 16-bit D/A converter
CLR PAEN
; disable power amplifier
MOV A,80H
;
MUTEB=1
to enable speaker; volume=
000_0000
MOV USVC, A
LOOP1:
