COP404C Datasheet, PDF (16/18 Pages) National Semiconductor (TI) – COP404C ROMless CMOS Microcontrollers

Emulation
The COP404C may be used to exactly emulate the
COP444C 445C COP424C 425C and COP410C 411C
However the Program Counter always addresses 2k of ex-
ternal ROM whatever chip is being emulated Figure 14
shows the interconnect to implement a hardware emulation
This connection uses a NMC27C16 EPROM as external
memory Other memory can be used such as bipolar PROM
or RAM
Pins IP7 – IP0 are bidirectional inputs and outputs When the
AD DATA clocking output turns on the EPROM drivers are
disabled and IP7 – IP0 output addresses The 8-bit latch
(MM74C373) latches the addresses to drive the memory
FIGURE 14 COP404C Used To Emulate A COP444C
TL DD 5530 – 14
16