UPD72001C datasheet(12/40 Pages) NEC

12 / 40 page

µPD72001-11, 72001-A8

Table 1-5. Auto Enable Bit and RTS Pin

Function

Protocol

Auto Enable Bit

RTS Cont. Bit

RTS Pin Status

Start-stop

synchronization

When “0” from beginning

If set to “1” once and then reset

If “L” while All SentNote = “0”,

to “0”

and “H” if All Sent = “1”

COP/BOP

Don’t Care

Note SR1: D2

1.2 Pins Related to Transmission/Reception

(1) TXDA (Transmit Data A) and TXDB (Transmit Data B) ... Output

These pins output transmit data.

(2) RxDA (Receive Data A) and RxDB (Receive Data B) ... Input

These pins input receive data.

(3) XI1A/STRXCA (Crystal Input 1A/Source of Transmit Receive Clock A) ... Input

XI1B/STRXCB (Crystal Input 1B/Source of Transmit Receive Clock B) ... Input

The functions of these pins change depending on the setting of CR15: D7.

(a) When CR15: D7 = “0”

These pins function as the STRXC pins, and input the transmission and reception clocks, or input source

clocks to the internal BRG (Baud Rate Generator) and DPLL (Digital Phase Locked Loop).

(b) When CR15: D7 = “1”

These pins function as XI1 pins and connect one end of the crystal for transmission/reception clock source

oscillation.

(4) XI2A/SYNCA (Crystal Input 2A/Synchronization A) ... I/O

XI2B/SYNCB (Crystal Input 2B/Synchronization B) ... I/O

The functions of these pins change depending on the setting of CR15: D7.

(a) When CR15: D7 = 0

These pins function as SYNC pins. The functions of the SYNC pins differ as shown in Table 1-6, depending

on the setting of CR4.

(b) When CR15: D7 = “1”

These pins function as XI2 pins and connect one end of the crystal for transmission/reception clock source

oscillation.

UPD72001C Datasheet(PDF) 12 Page - NEC