UPD72001-A8 NEC [NEC], UPD72001-A8 Datasheet - Page 11

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

(18) CTSA (Clear to Send A) and CTSB (Clear to Send B) ... Input
(19) DCDA (Data Carrier Detect A) ... Input
(20) RTSA (Request to Send A) ... Output
This pin is a general-purpose input pin and can be used to control a modem, etc. Changes in the status of this
pin affect the latching operation of the E/S bit. When E/S INT is enabled (CR1: D0 = “1”), the E/S interrupt is
generated.
If the Auto Enable mode (CR3: D5 = “1”) is set, the transmitter can be controlled by using the T
D3) and this pin. This is illustrated in Table 1-3.
DCDB (Data Carrier Detect B) ... Input
These are general-purpose input pins and can be used to control a modem, etc. Changes in the status of this
pin affect the latching operation of the E/S bit. When E/S INT is enabled (CR1: D0 = “1”), the E/S interrupt is
generated.
If the Auto Enable mode (CR3: D5 = “1”) is set, the receiver can be controlled by using the R
D0) and this pin. This is illustrated in Table 1-4.
RTSB (Request to Send B) ... Output
These are general-purpose output pins and can be used to control a modem, etc. The operations of these pins
differ depending on the setting of the operation protocol and the setting of the Auto Enable bit, as shown in Table
1-5.
(a) When CR2A: D1, D0 = “0, 0” or “0, 1”
(b) When CR2A: D1, D0 = “1, 0”
This pin functions as the DTRB output pin. The function of this pin is the same as the DTRA pin, except this
pin is used with channel B.
This pin functions as the DRQR
this pin is used with channel B.
DCD Pin
CTS Pin
H or L
H or L
H
H
L
L
Table 1-4. Auto Enable Mode and DCD Pin
Table 1-3. Auto Enable Mode and CTS Pin
X
B output pin. The function of this pin is the same as the DRQRxA pin, except
R
T
X
X
Enable Bit
Enable Bit
1
1
0
1
1
0
Transmitter Status
Receiver Status
PD72001-11, 72001-A8
Disabled
Disabled
Disabled
Disabled
Enabled
Enabled
X
X
Enable bit (CR3:
Enable bit (CR5:
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