UPD17134A Datasheet, PDF (36/292 Pages) NEC – 4-BIT SINGLE-CHIP MICROCONTROLLER

CHAPTER 3 PROGRAM COUNTER (PC)
The program counter is used to specify an address in program memory.
3.1 PROGRAM COUNTER CONFIGURATION
Figure 3-1 shows the configuration of the program counter.
The program counters of the µPD17134A and µPD17135A are 10-bit binary counters.
The program counters of the µPD17136A, µPD17137A, µPD17P136A, and µPD17P137A are 11-bit binary
counters.
This program counter is incremented whenever an instruction is executed.
Figure 3-1. Program Counter
MSB
LSB
PC10 PC9 PC8 PC7 PC6 PC5 PC4 PC3 PC2 PC1 PC0
PC
Remark The shaded part is effective only in the case of µPD17136A/17137A/17P136A/17P137A.
3.2 PROGRAM COUNTER OPERATION
Normally, the program counter is automatically incremented each time a command is executed. The memory
address at which the next instruction to be executed is stored is assigned to the program counter under the following
conditions: At reset; when a branch, subroutine call, return, or table reference instruction is executed; or when an
interrupt is received.
3.2.1 to 3.2.7 explain program counter operation during execution of each instruction.
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