Serial Interface - Oki PACEMARK 4410 Maintenance Manual

2.1.6

Serial Interface

The MPU sets the baud rate which is selected with the menu switch for the NHDC LSI and have
the serial I/F LSI to output the clock frequency of the baud rate.
Input signals from the serial I/F (DSR, CTS, CD and RD) are converted into TTL level ones by the
Line driver/receiver and input to the serial I/F LSI and NHDC LSI. The serial I/F LSI converts serial
data into parallel data to output it to the MPU.
Output signals (DTR, RTS, SSD and TD) to the serial I/F are output from the MPU to the NHDC
LSI and serial I/F LSI, and then converted through the Line driver/receiver into line voltage which
is output to the serial I/F.
MPU
DSR
RD
SSD
40496501TH Rev.1
AD0-AD7
NHDC LSI
TCK0
RTSN
SSDN
DTRN
CTSN
DSRN
DCDN
ST
Figure 2.9
Line
driver
Serial I/F LSI
receiver
CLK TXDA
RXDA
Serial I/F
TD
RD
RTS
SSD
DTR
CTS
DSR
CD
SP
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