ht82a836r Holtek Semiconductor Inc., ht82a836r Datasheet - Page 44

• Manufacturer Part Number: ht82a836r
• Description: Usb Audio Mcu
• Manufacturer: Holtek Semiconductor Inc.

REC_MODE=1:Writing to RECORD_IN_L register will only put the written data to an internal lower-order byte buffer
(8-bit) and writing RECORD_IN_H will transfer the RECORD_IN_L and RECORD_IN_H registers content to
isochronous in buffer. When record interrupt happened, firmware should write 16-bit 2 s complement value to RE-
CORD_IN_L and RECORD_IN_H (RECORD_U_EN=0) registers or write 8-bit law value to RECORD_IN_H register
(RECORD_U_EN=1).
The record write data format will be controlled by bit RECORD_U_EN of OPER_MODE register when REC_MODE=
The record data write format as follow:
Example Program to Eliminate Pop Noise:
System_Initial:
;-----------------------------------------------------------
; Avoid Pop Noise
;-----------------------------------------------------------
mov a,WDTS
mov FIFO_TEMP,a
mov a,00001111b
mov a,WDTS
mov a,01010000b
orm a,WDTS
clr [02DH]
mov a,80H
mov [02EH],a
;Write 8000H to DAC
set [02FH].3
clr [02FH].3
;-----------------------------------------------------------
mov a,FIFO_TEMP ;Restore WDTS value
mov WDTS,a ;Quit DAC Write Data mode
;-----------------------------------------------------------
Rev. 1.00
1 .
REC_MODE= 1
REC_MODE= 0
RECORD_U_EN= 0
RECORD_U_EN= 1
Record data comes from the RECORD_IN_H and RECORD_IN_L registers
Record data comes from the PCM ADC (Default =0)
;Enter DAC Write Data mode, high nibble of WDTS=0101b
;Set DAC data low byte=00H
;Set DAC data high byte=80H
;Save WDTS value
PCM (Low byte)
RECORD_IN_L
N/A
44
PCM (High byte)
RECORD_IN_H
Law
HT82A836R
March 20, 2008