HT36A1 Holtek Semiconductor Inc., HT36A1 Datasheet - Page 17

• Manufacturer Part Number: HT36A1
• Description: Ht36a1 -- Music Synthesizer 8-bit Mcu
• Manufacturer: Holtek Semiconductor Inc.

Rev. 1.10
Envelope type definition
The HT36A1 provides a function to easily program the
envelope by setting the data of ENV1~0 and A_R. It
forms a vibrato effect by a change of the volume to at-
tach and release alternately.
The A_R signal is used to define the volume change in
attach mode or release mode and ENV1~0 is used to
define which volume control bit will be changeable. On
the attach mode, the control bits will be sequentially
signaled down to 0. On the release mode, the control
bits will be sequentially signaled up to 1. The relation-
ship is shown in the following table.
The PCM code definition
The HT36A1 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.
A_R
0
0
0
1
1
1
x
ENV1
0
0
1
1
0
0
1
ENV0
0
1
0
1
0
1
0
Volume Control Bit
Envelope Type Definition
VR2~0
VR1~0
VR2~0
VR1~0
No Bit
VR0
VR0
17
Mask Option
No.
1
2
3
4
5
Control Bit Final Value
WDT source
CLRWDT times
Wake-up
Pull-High
OSC mode
unchanged
Mask Option
111b
000b
11b
00b
1b
0b
On-chip RC/Instruction
clock/disable WDT
One time, two times
(CLR WDT1/WDT2)
PA only
PA, PB, PC input
Crystal or Resistor type
Release mode
No change mode
Attach mode
Function
March 12, 2007
Mode
HT36A1