An integrated circuit contains a microprocessor core, program memory and separate
data storage, together with analog and digital signal processing circuitry. The
ALU is 16 bits wide, but a 32-bit shift unit is provided, using a pair of 16-bit
registers. The processor has a fixed length instruction format, with an instruction
set including multiply and divide operations which use the shift unit over several
cycles. No interrupts are provided. external pins of the integrated circuit allow
for single stepping and other debug operations, and a serial interface (SIF) which
allows external communication of test dat or working data as necessary. The serial
interface has four wires (SERIN, SEROUT, SERCLK, SERLOADB), allowing handshaking
with a master apparatus, and allowing direct access to the memory space of the
processor core, without specific program control. Within each processor cycle,
the processor circuitry is divided into plural stages, and latches are interposed
between the stages to minimize power consumption.
