SN66120B
4-Channel Speech Controller
5 FUNCTION DESCRIPTIONS
5.1. Oscillator
SN66120B 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
20pf
OSC/XIN
XOUT
OSC/XIN
XOUT
CKSEL
CKSEL
2MHz
20pf
Crystal / Resonator
RC Oscillator
5.2. ROM
SN66120B contains 384K word (12-bit) internal ROM. Program, voices, melodies,
data, and instrument waveforms share the same ROM with the others.
5.3. RAM
SN66120B contains 128 nibble RAM. The 128 nibble RAM is separated into two
pages (page 0 and page 1). An implicit page indicator is utilized to specify page
address. Two instructions, PAGE0 and PAGE1, can switch the page indicator. All 64
nibbles of each page can be accessed by direct mode (to specify M0 ~ M63 in the data
transfer type instructions.)
5.4. Power Down Mode
“End” instruction will let SN66120B enter power down mode and consumer very little
amount of current. (<2uA @VDD=3V and <5uA @VDD=5V) After SN66120B enters
power down mode, any valid data transition (LꢁH or HꢁL) occurring on any input
ports or IO ports (P1, P2, and P3) lead SN66120B back to normal operation mode.
3
Ver: 1.1
December 6, 2004
SONIX [ SONIX TECHNOLOGY COMPANY ]
