HT37Q70 Holtek Semiconductor Inc., HT37Q70 Datasheet - Page 55

• Manufacturer Part Number: HT37Q70
• Description: 4-channel Music Synthesizer Mcu
• Manufacturer: Holtek Semiconductor Inc.

Waveform Format Definition
Each device accepts two waveform formats to ensure a
more economical data space. WBS is used to define the
sample format of each PCM code.
WBS=0 means the sample format is 8-bit (PCM8)
WBS=1 means the sample format is 12-bit (PCM12)
The 12-bit sample format allocates location to each
sample data. Please refer to the waveform format state-
ment as shown below.
ADPCM
Rev. 1.00
20H
21H
22H
23H
24H
25H
26H
27H
28H
29H
2AH
Address Offset
Name
30H
31H
32H
33H
34H
Channel number selection (CHAN)
Frequency number high byte (FreqNH)
Frequency number low byte (FreqNL)
Start address high byte (AddrH)
Start address low byte (AddrL)
Repeat number high byte (RepH)
Repeat number low byte (RepL)
Control register (ENV)
Right volume control (RVC)
Register Name
ADPC
XSPH
ADPS
XSPL
ADR
Function
Wavetable Register Memory Map (20h~2Ah)
HT-ADPCM Decoder Registers
R/W
R/W
W
W
W
R
WBS RE14 RE13 RE12 RE11 RE10
FR7
ST7
RE7
A_R
VR7
BL3
VM
D7
55
Default Value
Repeat Number Definition
The repeat number is used to define the address which
is the repeat point of the sample. When the repeat num-
ber is defined, it will be output from the start code to the
end code once and always output the range between
the repeat address to the end code (80H) until the vol-
ume become close. The RE14~RE0 is used to calculate
the repeat address of the PCM code. The process for
setting the RE14~RE0 is to write the 2 s complement of
the repeat length to RE14~RE0, with the highest carry
ignored. The HT37 will get the repeat address by adding
the RE14~RE0 to the address of the end code, then
jump to the address to repeat this range.
Volume Control
Each device provides the volume control independently.
The volume are controlled by VR9~VR0 respectively.
The chip provides 1024 levels of controllable volume,
the 000H is the maximum and 3FFH is the minimum out-
put volume. The PCM code definition Each device can
only solve the voice format of the signed 8-bit or 12-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.
0000 0000
0000 0000
0000 1111
00x0 xx00
RE6
VR6
xxxx xxxx
BL2
FR6
ST6
D6
FR
ST13 ST12 ST11 ST10
FR5
RE5
VR5
BL1
ST5
D5
HT37Q70/60/50/40/30/20
VR4
FR4
ST4
RE4
BL0
D4
ADPCM Data Register
Xn + SP Initial Register Low Byte
Xn + SP Initial Register High Byte
ADPCM Decoder control register
ADPCM Decoder Status Register
ENV1 ENV0
FR11 FR10
RE3
VR3
FR3
ST3
D3
Description
FR2
RE2
VR2
ST2
D2
February 17, 2009
CH1
RE9
RE1
VR9
VR1
FR9
FR1
ST9
ST1
D1
CH0
FR8
FR0
RE8
RE0
VR8
VR0
ST8
ST0
D0