Renesas PCA7401 Technické informace stáhnout pdf (Strana 20)

MITSUBISHI MICROCOMPUTERS

M37270MF-XXXSP

M37270EF-XXXSP, M37270EFSP

SINGLE-CHIP 8-BIT CMOS MICROCOMPUTER with CLOSED CAPTION DECODER

and ON-SCREEN DISPLAY CONTROLLER

SERIAL I/O

The M37270MF-XXXSP has a built-in serial I/O which can either trans-

mit or receive 8-bit data in serial in the clock synchronous mode.

The serial I/O block diagram is shown in Figure 9. The synchronizing

clock I/O pin (S

CLK), and data output pin (SOUT) also function as port

P4, data input pin (S

IN) also functions as port P1.

Bit 2 of the serial I/O mode register (address 0213

16) selects whether

the synchronizing clock is supplied internally or externally (from the

6/SCLK pin). When an internal clock is selected, bits 1 and 0 select

whether f(X

IN) or f(XCIN) is divided by 8, 16, 32, or 64. To use P45/

OUT and P46/SCLK pins for serial I/O, set the corresponding bits of

the port P4 direction register (address 00C9

16) to “0.” To use P17/SIN

pin for serial I/O, set the corresponding bit of the port P1 direction

16) to “0.”

Fig. 9. Serial I/O block diagram

The operation of the serial I/O function is described below. The func-

tion of the serial I/O differs depending on the clock source; external

clock or internal clock.

Serial I/O shift register (8)

Data bus

Serial I/O

interrupt request

Selection gate: Connect to

black colored

side at reset.

Synchronization

circuit

Frequency divider

1/81/4 1/16

SM1

SM0

Serial I/O counter (8)

5 : LSB

MSB

SM2

1/2

P17/SIN

P45/SOUT

P46/SCLK

1/2

(Address 021416)

XCIN

1/2

CM7

1/2

Note : When the data is set in the serial I/O register (address 021416), the register functions as the serial I/O shift register.

(Note)

CM : CPU mode register

SM : Serial I/O mode register

1 2 ... 15 16 17 18 19 20 21 22 23 24 25 ... 96 97

Komentáře k této Příručce

Žádné komentáře

Renesas PCA7401 Technické informace Strana 20

Komentáře k této Příručce