FUJITSU Semiconductor Controller MB89950/950A - Manual (Page 86)

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CHAPTER 4 I/O PORTS
4.2 Port 0
Port 0 is N-ch open-drain I/O port that also serves as LCD segment driver outputs. Port
0 pins can be switched between LCD segment driver output and port operation by mask
option. This section principally describes the port functions when operating as N-ch
open-drain I/O port.
The section describes the port structure and pins, the pin block diagram, and the port
register for port 0.
■ Structure of port 0
Port 0 consists of the following two components:
• N-ch open-drain I/O pins/LCD segment driver output pins (P00/SEG20 to P07/SEG27)
• Port 0 data register (PDR0)
■ Port 0 pins
Port 0 consists of eight N-ch open-drain I/O. When pins are used by the peripheral, they cannot be used as
N-ch open-drain I/O.
Table 4.2-1 "Port 0 pins" lists the port 0 pins.
See Section 1.7 "I/O Pins and Pin Functions" for a description of the circuit type.
Table 4.2-1 Port 0 pins
Port Pin name Function Shared peripheral
I/O type
Circuit
type
Input Output
Port 0
P00/SEG20 P00 N-ch open-drain I/O SEG20 LCD segment driver output
CMOS
Segment / N-ch
open-drain
D
P01/SEG21 P01 N-ch open-drain I/O SEG21 LCD segment driver output
P02/SEG22 P02 N-ch open-drain I/O SEG22 LCD segment driver output
P03/SEG23 P03 N-ch open-drain I/O SEG23 LCD segment driver output
P04/SEG24 P04 N-ch open-drain I/O SEG24 LCD segment driver output
P05/SEG25 P05 N-ch open-drain I/O SEG25 LCD segment driver output
P06/SEG26 P06 N-ch open-drain I/O SEG26 LCD segment driver output
P07/SEG27 P07 N-ch open-drain I/O SEG27 LCD segment driver output