M34280M1-XXXFP View Datasheet(PDF) - Renesas Electronics

Part Name

Description

Manufacturer

M34280M1-XXXFP

SINGLE-CHIP 4-BIT CMOS MICROCOMPUTER for INFRARED REMOTE CONTROL TRANSMITTERS

Renesas Electronics 

MITSUBISHI MICROCOMPUTERS

4280 Group

SINGLE-CHIP 4-BIT CMOS MICROCOMPUTER for INFRARED REMOTE CONTROL TRANSMITTERS

(8) Program counter (PC)

Program counter (PC) is used to specify a ROM address (page

and address). It determines a sequence in which instructions

stored in ROM are read. It is a binary counter that increments

the number of instruction bytes each time an instruction is

executed. However, the value changes to a specified address

when branch instructions, subroutine call instructions, return

instructions, or the table reference instruction (TABP p) is

executed.

Program counter consists of PCH (most significant bit to bit 7)

which specifies to a ROM page and PCL (bits 6 to 0) which

specifies an address within a page. After it reaches the last

address (address 127) of a page, it specifies address 0 of the

next page (Figure 7).

Make sure that the PCH does not exceed after the last page of

the built-in ROM.

(9) Data pointer (DP)

Data pointer (DP) is used to specify a RAM address and

consists of registers X and Y. Register X specifies a file and

register Y specifies a RAM digit (Figure 8).

Register Y is also used to specify the port D bit position.

When using port D, set the port D bit position to register Y

certainly and execute the SD, RD, or SZD instruction (Figure

9).

Program counter (PC)

p3 p2 p1 p0 a6 a5 a4 a3 a2 a1 a0

PCH

Specifying

page

PCL

Specifying address

Fig. 7 Program counter (PC) structure

Data pointer (DP)

X1 X0 Y3 Y2 Y1 Y0

Register Y (4) Specifying

RAM digit

Register X (2)

Specifying RAM file

Fig. 8 Data pointer (DP) structure

Specifying bit position

Set

0101

Register Y (4)

D7

D5

D0

1

Port D output latch

Fig. 9 SD instruction execution example

8

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