The PIC manage
the RAM, two internal ADC for CV-Wave/Bank selection,
MIDI I/O and control the Zero Crossing Detector ( ZCD).The
memory is a 4Mbits SRAM with a latency time of 70nsec.
RAM and eprom read data cycles are almost identical. In
'RAM edit' mode, the PIC control 18 RAM adresses via a
set of latches. A PIC port is wired to the RAM datas I/Os
and to the output DAC. The DAC range is
selected by a switch to be positive only '+10V' or symetrical 'AC'
' (+/-5V)
When
the RAM is not used by the PIC for edition purposes, lower
8 bits of RAM adresses (lsb) are controled by the fast
A/D converter.The Quantix-8 main input is a 8bits/1Mbps A/D
converter with a Zero Crossing Detector for noise-free
waveform changes. Both stages are very fast.
Hi
adresses (msb) are set by the Bank / Waves CVs, converted
to digital by two A/D converters inside the PIC. The selected
waveform number is available on a 20 pins connector. Various
systems can be connected here to display this value.
To
limit power supply consumption the bank/waves display
is binary made with 2mA leds. This way the +5V to feed
logic circuits can be extracted from the +15V connector
without any thermal problems.A 3V Lithium battery keep
memory datas when power is off.
Download the Quantix-8 schematic only v1.0 (pdf)