UPD72001-A8 NEC [NEC], UPD72001-A8 Datasheet - Page 12

• Manufacturer Part Number: UPD72001-A8
• Description: MULTI-PROTOCOL SERIAL CONTROLLERS
• Manufacturer: NEC [NEC]

1.2 Pins Related to Transmission/Reception
(1) T
(2) RxDA (Receive Data A) and RxDB (Receive Data B) ... Input
(3) XI1A/STR
(4) XI2A/SYNCA (Crystal Input 2A/Synchronization A) ... I/O
12
Protocol
Start-stop
synchronization
COP/BOP
Note SR1: D2
These pins output transmit data.
These pins input receive data.
XI1B/STR
The functions of these pins change depending on the setting of CR15: D7.
(a) When CR15: D7 = “0”
(b) When CR15: D7 = “1”
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
(b) When CR15: D7 = “1”
X
DA (Transmit Data A) and T
These pins function as the STR
clocks to the internal BRG (Baud Rate Generator) and DPLL (Digital Phase Locked Loop).
These pins function as XI1 pins and connect one end of the crystal for transmission/reception clock source
oscillation.
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.
These pins function as XI2 pins and connect one end of the crystal for transmission/reception clock source
oscillation.
Function
X
X
CA (Crystal Input 1A/Source of Transmit Receive Clock A) ... Input
CB (Crystal Input 1B/Source of Transmit Receive Clock B) ... Input
Auto Enable Bit
Don’t Care
0
1
X
Table 1-5. Auto Enable Bit and RTS Pin
DB (Transmit Data B) ... Output
X
C pins, and input the transmission and reception clocks, or input source
If set to “1” once and then reset
to “0”
When “0” from beginning
RTS Cont. Bit
0
1
1
0
1
If “L” while All Sent
and “H” if All Sent = “1”
PD72001-11, 72001-A8
RTS Pin Status
H
H
H
L
L
L
Note
= “0”,