SN56030

4-Channel Speech Controller

5.

FUNCTION DESCRIPTIONS

5.1. Oscillator

SN56000 series accepts crystal oscillator / ceramic resonator or RC type oscillator

(selected by pin CKSEL) for system clock. The typical circuit diagrams for oscillator

are listed as follows.

OSC/XIN

CKSEL

XOUT

VDD

RC Oscillator

Crystal / Resonator

VDD

OSC/XIN

CKSEL

XOUT

15pf

2MHz

SN56000

SN56000

15pf

5.2. ROM

SN56030 contains 96K word (10-bit) internal ROM. Program, voices, melodies, data,

and instrument waveforms share the same ROM with the others.

5.3. RAM

SN56000 series contains 128 nibble RAM. The 128 nibble RAM is separated into

eight pages (page 0, page1… page 7). An implicit page indicator is utilized to specify

page address. Eight instructions, PAGE0, PAGE1... PAGE7 can switch the page

indicator. All 16 nibbles of each page can be accessed by direct mode (to specify M0

~ M15 in the data transfer type instructions.)

5.4. Power Down Mode

“End” instruction will let SN56000 series enter power down mode and consumer very

little amount of current. (<2uA @VDD=3V and <5uA @VDD=5V) After SN56030

enters power down mode, any valid data transition (L H or H L) occurring on any

input ports or IO ports (P1, P2, P3 and P6) lead SN56000 series back to normal

operation mode.

5.5. Sampling Rate Counters

4 independent sampling rate counters are dedicated to 4 individual voice channels to

play voices with different playing rates. The playing rate is programmable from 4KHz

to 40KHz. The resolution of sampling period of each sampling rate counter is 0.25 uS.

This feature helps SN56000 series play sounds with accurate pitches in the case of

music instrument synthesis.

Ver: 1.0

March 2,2005

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