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Data Sheet
RSC-4128
19
P/N 80-0206-R
© 2006 Sensory Inc.
On-Chip ROM
The RSC-4128 includes integrated on-chip ROM. This ROM is enabled when the –XM pin is tied , or pulled high by
it’s own internal pullup resistor. This ROM space can combine both Code and Data.
ROM code Security Feature
The RSC-4128 has only one external memory enable pin (-XM), designed to prevent configuring code space for
both internal and external memory. This discourages executing external code that reads internal code via the
MOVC instruction and dumps it externally.
In this way, a substantial measure of security is provided for the
developer’s application code.
Oscillators
Two independent oscillators in the RSC-4128 provide a high-frequency oscillator (OSC1), and a 32 KHz time-
keeping and power-saving oscillator (OSC2). The oscillator characteristics are:
OSC
FREQ
PLL PINS
SOURCES
1
3.58 MHz 4X
XI1
XO1
Crystal
Ceramic resonator
LC
2
32768 Hz N/A
XI2
XO2
Crystal
Internal RC