µPD72001-11, 72001-A8

11

(a) When CR2A: D1, D0 = “0, 0” or “0, 1”

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.

(b) When CR2A: D1, D0 = “1, 0”

this pin is used with channel B.

(18) CTSA (Clear to Send A) and CTSB (Clear to Send B) ... Input

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.

D3) and this pin. This is illustrated in Table 1-3.

Table 1-3. Auto Enable Mode and CTS Pin

CTS Pin

Transmitter Status

L

1

Enabled

H

1

Disabled

H or L

0

Disabled

(19) DCDA (Data Carrier Detect A) ... Input

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.

D0) and this pin. This is illustrated in Table 1-4.

Table 1-4. Auto Enable Mode and DCD Pin

DCD Pin

Receiver Status

L

1

Enabled

H

1

Disabled

H or L

0

Disabled

(20) RTSA (Request to Send A) ... Output

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.