4570 datasheet(11/69 Pages) RENESAS

11 / 69 page

MITSUBISHI MICROCOMPUTERS

4570 Group

SINGLE-CHIP 4-BIT CMOS MICROCOMPUTER

Fig. 7 Program counter (PC) structure

Fig. 8 Data pointer (DP) structure

Fig. 9 SD instruction execution example

(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 specify 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 Z, X, and Y. Register Z specifies a RAM

file group, register X specifies a file, and register Y specifies

a RAM digit (Figure 8).

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

certainly and execute the SD or RD instruction (Figure 9).

Z1 Z0 X3 X2 X1 X0 Y3 Y2 Y1 Y0

Data pointer (DP)

Specifying

RAM digit

Specifying RAM file

Specifying RAM file group

p5 p4 p3 p2 p1 p0

a6 a5 a4 a3 a2 a1 a0

Program counter (PC)

PCH

Specifying page

PCL

Specifying address

Set

Specifying bit position

Port D output latch

4570 Datasheet(PDF) 11 Page - Renesas Technology Corp

4570 Datasheet(HTML) 11 Page - Renesas Technology Corp

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69

Datasheet Download

Link URL