SNC384
Direct Drive Voice/Dual Tone Melody Controller
5
FUNCTION DESCRIPTIONS
5.1. Oscillator
SNC384 accept RC type oscillator for system clock. The typical circuit diagram for
oscillator is listed as follow.
VCC
RC Oscillator
5.2. ROM
SNC384 contains substantial 184K words (10-bit) internal ROM. Program, voices and
other data are shared with this same 184K words ROM.
5.3. RAM
SNC384 contains 128 nibbles RAM. The 128 nibbles RAM are divided into eight
pages (page 0 to page 7, 16 nibbles RAM on each page). In our programming
structure, users can easily define and locate RAM page in the program. For instance,
users can use the instructions, PAGEn (n=0 to 7) to switch and indicate the RAM page.
Besides, users can use direct mode, M0 ~ M15 in the data transfer type instructions, to
access all 16 nibbles of each page.
5.4. Power Down Mode
“End” instruction will power down SNC384 and enable IC to consume fewer current for
power saving. (<3uA @VDD=3V and <5uA @VDD=5V) Please be aware that when
the power down mode is activated in SNC384, any valid data transition (L H or H L)
occurring on any input port (P1) or IO ports (P2, P3 and P6) will lead SNC384 back to
normal operation mode.
5.5. Sampling Rate Counter
The unique sampling rate counter is designed in voice channel to be able to play
diverse voices at different sample playing rates. The playing rate can be adaptively
set up among from the wide ranges of 2.5KHz to 20KHz. This feature makes voice
close to its original source and yield the better voice quality.
Ver: 1.4
3
r
June 8, 2005
OSC