HT36M4

Rev. 1.10

17

March 14, 2007

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.

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.

Bit No.

Label

Function

Bit7~Bit3

¾

Unused

Bit2

¾

Unused

Bit1

DANO

DAON=1: DAC ON

DAON=0: DAC OFF (Default)

Bit0

SELWR

SELWR=1: Right Channel DAC data from Wavetable

SELWR=0: Right Channel DAC data from MCU (default)

DAC (1FH) Control Regulation

Mask Option

No

Mask Option

Description

1

WDT Source

On-chip RC/instruction clock/disable WDT

2

CLRWDT Times

One time, two times (CLR WDT1/WDT2)

3

Wake-up

PA only

4

Pull-high

PA, PB0~PB3 input

5

OSC Mode

Crystal or resistor type

6

LVR

Enable or disable

A_R

ENV1

ENV0

Volume Control Bit

Control Bit Final Value

Mode

0

0

0

VL2~VL0, VR2~VR0

111b

Release mode

0

0

1

VL1~VL0, VR1~VR0

11b

0

1

0

VL0, VR0

1b

x

1

1

No Bit

Unchanged

No change mode

1

0

0

VL2~VL0, VR2~VR0

000b

Attach mode

1

0

1

VL1~VL0, VR1~VR0

00b

1

1

0

VL0, VR0

0b

Envelope Type Definition