DMC73C167 datasheet(19/90 Pages) DAEWOO

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8Bit Single Chip Microcontroller

DMC73C167

The C, N and Z bits are used mostly for arithmetic operations, bit rotating, and conditional

branching. The carry (C) bit is used as the carry-in and the carry-out for most of the rotate

and arithmetic instructions. The sign(N) bit contains the most significant bit of the

desitination operand contents after instruction execution. The zero(Z) bit contains a 1 when

all bits of the destination operand are equal to zero after instruction execution.

The C, N, and Z status bits also have jump-on-condition instructions associated with them.

The global interrupt enable(I) bit must be set to 1 by the EINT instruction in order for any of

the individual interrupts (INTn) to be recognized by the CPU. The interrupt enable(I) bit can

be cleared by the DINT instruction or by execuiting a device RESET (see Section 4.8).

4.6 Program Counter (PC)

The DMC73C167's 16-bit program counter (PC) consists of two 8-bit registers in the

CPU which contain the MSB and the LSB, respectively, of a 16-bit address , the program

counter high (PCH) and program counter low (PCL). The PC acts as the 16-bit address

pointer of the opcodes and operands in the memory of the currently executing instruction.

Upon assertion of the RESET function, the MSB and the LSB of the PC are loaded into the

A and B registers of the register file (see Section 4.8).

4.7 Peripheral File Map

The peripheral file(PF) resides in location 0100h through 01FFh of the DMC73C167's

address space, as shown in Tables 4-2.

Note : The right-end column, headed "Value After Reset", indicates a reset initial value as

shown in Table 4-1.

Table 4-1. Description of "Value After Reset"

MSB

LSB

Becomes value "1" after RESET

Becomes value "0" after RESET

Unkown value after RESET

Not Used

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