COP8AME9 Datasheet, PDF (16/83 Pages) National Semiconductor (TI) – 8-Bit CMOS Flash Microcontroller with 8k Memory, Dual Op Amps, Virtual EEROM, Temperature Sensor,10-Bit A/D and Brownout Reset

9.0 Pin Descriptions (Continued)
Speed Oscillator Output)
L0 Multi-Input Wake-up (Low Speed Oscillator Input)
nector can be designed into the production PC board and
can be replaced by jumpers or signal traces when emulation
is no longer necessary.
The emulator will replicate all functions of G0 - G3 and
Reset. For proper operation, no connection should be made
on the device side of the emulator connector.
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FIGURE 2. I/O Port Configurations
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FIGURE 3. I/O Port Configurations — Output Mode
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FIGURE 4. I/O Port Configurations — Input Mode
9.1 EMULATION CONNECTION
Connection to the emulation system is made via a 2 x 7
connector which interrupts the continuity of the RESET, G0,
G1, G2 and G3 signals between the COP8 device and the
rest of the target system (as shown in Figure 5). This con-
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FIGURE 5. Emulation Connection
10.0 Functional Description
The architecture of the device is a modified Harvard archi-
tecture. With the Harvard architecture, the program memory
(Flash) is separate from the data store memory (RAM). Both
Program Memory and Data Memory have their own separate
addressing space with separate address buses. The archi-
tecture, though based on the Harvard architecture, permits
transfer of data from Flash Memory to RAM.
10.1 CPU REGISTERS
The CPU can do an 8-bit addition, subtraction, logical or shift
operation in one instruction (t_C) cycle time.
There are six CPU registers:
A is the 8-bit Accumulator Register
PC is the 15-bit Program Counter Register
PU is the upper 7 bits of the program counter (PC)
PL is the lower 8 bits of the program counter (PC)
B is an 8-bit RAM address pointer, which can be optionally
post auto incremented or decremented.
X is an 8-bit alternate RAM address pointer, which can be
optionally post auto incremented or decremented.
S is the 8-bit Data Segment Address Register used to extend
the lower half of the address range (00 to 7F) into 256 data
segments of 128 bytes each.
SP is the 8-bit stack pointer, which points to the subroutine/
interrupt stack (in RAM). With reset the SP is initialized to
RAM address 06F Hex. The SP is decremented as items are
pushed onto the stack. SP points to the next available loca-
tion on the stack.
All the CPU registers are memory mapped with the excep-
tion of the Accumulator (A) and the Program Counter (PC).
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