Iwatsu ADIX VS Owner's Manual page 34

Highway Controller. The VS-CPUMEM has one two-way highway
consisting of thirty-two PCM time division multiplexed data channels. This
two-way highway channel provides voice and data communication through
the system ports. A 16 MHz microprocessor controls the PCM highways
with the aid of a slave processor that directly communicates with the CPU.
ADIX-VS Operating System. The VS-CPUMEM contains the
68EC020/25 MHz Central Processing Unit (CPU) and also 4MB of Intel ®
flash memory that stores the ADIX-VS operating system.
ADIX-VS General Description - 24