HT36M4 Holtek Semiconductor Inc., HT36M4 Datasheet - Page 17

• Manufacturer Part Number: HT36M4
• Description: Ht36m4 -- Music Synthesizer 8-bit Mcu
• Manufacturer: Holtek Semiconductor Inc.

Digital to Analog Converter (DAC)
The HT36M4 provides one 16-bit voltage type DAC device controlled by the MCU or wavetable synthesizer for driving
an external speaker through an external NPN transistor. It is in fact an optional object used for Wavetable Synthesizer
DAC or general DAC, this is chosen by DAC control register. If general DAC is chosen for application, then Wavetable
synthesizer is disabled because the DAC is taken up and controlled by the MCU. If general DAC is selected, the pro-
grammer must write the voice data to register DAL and DAH to get the corresponding analog data. If Mask Option en-
ables the DAC register and enables the SELW, then the following table comes useful.
Mask Option
Rev. 1.10
The PCM code definition
The HT36M4 can only solve the voice format of the signed 8-bit raw PCM. And the MCU will take the voice code 80H
as the end code.
So each PCM code section must be ended with the end code 80H.
Bit7~Bit3
No
A_R
Bit No.
1
2
3
4
5
6
0
0
0
x
1
1
1
Bit2
Bit1
Bit0
WDT Source
CLRWDT Times
Wake-up
Pull-high
OSC Mode
LVR
Mask Option
ENV1
0
0
1
1
0
0
1
SELWR
DANO
Label
ENV0
0
1
0
1
0
1
0
Unused
Unused
DAON=1: DAC ON
DAON=0: DAC OFF (Default)
SELWR=1: Right Channel DAC data from Wavetable
SELWR=0: Right Channel DAC data from MCU (default)
On-chip RC/instruction clock/disable WDT
One time, two times (CLR WDT1/WDT2)
PA only
PA, PB0~PB3 input
Crystal or resistor type
Enable or disable
VL2~VL0, VR2~VR0
VL1~VL0, VR1~VR0
VL2~VL0, VR2~VR0
VL1~VL0, VR1~VR0
Volume Control Bit
VL0, VR0
VL0, VR0
DAC (1FH) Control Regulation
No Bit
Envelope Type Definition
17
Control Bit Final Value
Description
Function
Unchanged
111b
000b
11b
00b
1b
0b
Release mode
No change mode
Attach mode
Mode
March 14, 2007
HT36M4