SN56020
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.
VDD
VDD
SN56000
CKSEL
OSC/XIN
XOUT
15pf
SN56000
CKSEL
OSC/XIN
XOUT
2MHz
Crystal / Resonator
5.2. ROM
15pf
RC Oscillator
SN56020 contains 64K 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 SN56020
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
5
March 2,2005
SONIX [ SONIX TECHNOLOGY COMPANY ]
