HT827A0 データシートの表示（PDF） - Holtek Semiconductor

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HT827A0

8-Bit Microcontroller with Voice ROM

Holtek Semiconductor 

Sampling rate counter

The HT827A0 offers a sampling rate counter.

This counter contains a 5 bit programmable

count-up counter. The clock may come from

128kHz or 2kHz by code option and the clock

base on 3.579545MHz system clock.

Labels

Bit

s

Function

SR0~

SR4

0~4

To define a voice sampling

rate or envelope decaying time

2K/

128K

5

To define an input clock

source (0=128K; 1=2K)

¾ 6~7 Unused bits, read as ²0²

SRC register

D ATA

BUS

128K

S a m p lin g R a te

C o u n te r

R E LO A D

P r e lo a d R e g is te r

2K

2 K /1 2 8 K

SRO N

S a m p lin g R a te

C o u n te r

¸1

C o u n te r

O V E R FLO W

to In te rru p t

Sample rate counter

When the 128kHz clock is selected, 26 kinds of

sampling rate are provided for a voice synthe-

sizer. The following is a table of the 26 kinds of

sampling rates:

Code

Freq.

Code

Freq.

xx00 0000 3.50kHz xx00 1101 5.89kHz

xx00 0001 3.61kHz xx00 1110 6.21kHz

xx00 0010 3.72kHz xx00 1111 6.58kHz

xx00 0011 3.86kHz xx01 0000 6.99kHz

xx00 0100 3.99kHz

xx00 0101 4.14kHz

xx00 0110 4.30kHz

xx00 0111 4.48kHz

xx00 1000 4.66kHz

xx00 1001 4.86kHz

xx01 0001 7.46kHz

xx01 0010 7.99kHz

xx01 0011 8.61kHz

xx01 0100 9.32kHz

xx01 0101 10.17kHz

xx01 0110 11.19kHz

HT827A0

Code

Freq.

xx00 1010 5.08kHz

xx00 1011 5.33kHz

xx00 1100 5.59kHz

Code

Freq.

xx01 0111 12.43kHz

xx01 1000 13.98kHz

xx01 1001 15.98kHz

Sampling rate table

Note: ²xx² means don¢t care

On the other hand, when the 2kHz clock is cho-

sen, 32 kinds of time periods of the envelope de-

cay is offered.

The following is a table of the envelope decay:

Code Freq.

Code

Freq.

xx10 0000 54.6Hz xx11 0000 109.3Hz

xx10 0001 56.4Hz xx11 0001 116.5Hz

xx10 0010 58.3Hz xx11 0010 124.9Hz

xx10 0011 60.3Hz xx11 0011 134.5Hz

xx10 0100 62.4Hz xx11 0100 145.7Hz

xx10 0101 64.7Hz xx11 0101 158.9Hz

xx10 0110 67.2Hz xx11 0110 174.8Hz

xx10 0111 69.9Hz xx11 0111 194.2Hz

xx10 1000 72.8Hz xx11 1000 218.5Hz

xx10 1001 76.0Hz xx11 1001 249.7Hz

xx10 1010 79.5Hz xx11 1010 291.3Hz

xx10 1011 83.2Hz xx11 1011 349.6Hz

xx10 1100 87.4Hz xx11 1100 437.0Hz

xx10 1101 92.0Hz xx11 1101 582.7Hz

xx10 1110 97.1Hz xx11 1110 874.0Hz

xx10 1111 102.8Hz xx11 1111 1.75kHz

Envelope decay table

Note: ²xx² means don¢t care

19

March 15, 2000

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