Block diagram of port 2 pins, Port 2 register – FUJITSU Semiconductor Controller MB89950/950A User Manual

Page 97

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CHAPTER 4 I/O PORTS

Block diagram of port 2 pins

Figure 4.4-1 Block diagram of port 2 pins

Port 2 register

The port 2 register consists of PDR2. Each bit in the register has a one-to-one relationship with a port 2 pin.

Table 4.4-2 "Correspondence between pin and register for port 2" shows the correspondence between the

pins and register for port 2.

PDR (Port data register)

In

te

rnal

dat

a

bus

PDR read (for bit manipulation instructions)

Output latch

PDR write

Pin

N-ch

Stop mode (SPL = 1)

SPL: Pin state specification bit in the standby control register (STBC)

PDR read

Stop mode (SPL = 1)

LCD segment driver output

Mask option

Segment driver output select register

Table 4.4-2 Correspondence between pin and register for port 2

Port

Correspondence between register bit and pin

Port 2

PDR2

Bit 7

Bit 6

Bit 5

Bit 4

Bit 3

Bit 2

Bit 1

Bit 0

Corresponding pin

--

--

P25

P24

P23

P22

P21

P20

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