Registers – Rainbow Electronics AT89C5122 User Manual

Page 61

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61

AT8xC5122/23

4202E–SCR–06/06

Registers

Reset Value = 0000 0x00b

Reset Value = 00xx 0xxxb

Table 36. Port Mode Register 0 - PMOD0 (91h) for AT8xC5122

7

6

5

4

3

2

1

0

P3C1

P3C0

P2C1

P2C0

CPRESRES

-

P0C1

P0C0

Bit Number

Bit Mnemonic Description

7 - 6

P3C1-P3C0

Port 3 Configuration bits (Applicable to P3.0, P3.1, P3.3, P3.4 only)

00 Quasi bi-directional

01 Push-pull

10 Output Low Speed

11 Input with weak pull-up

5-4

P2C1-P2C0

Port 2 Configuration bits

00 Quasi bi-directional

01 Push-pull

10 Output Low Speed

11 Input with weak pull-down

3

CPRESRES

Card Presence Pull-up resistor

Cleared to connect the internal 100K pull-up

Set to disconnect the internal pull-up

2

-

Reserved
The value read from this bit is indeterminate. Do not set this bit.

1-0

P0C1-P0C0

Port 0 Configuration bits

00 C51 Standard P0

01 Reserved

10 Output Low Speed

11 Push-pull

Table 37. Port Mode Register 0 - PMOD0 (91h) for AT83C5123

7

6

5

4

3

2

1

0

P3C1

P3C0

-

-

CPRESRES

-

-

-

Bit Number

Bit Mnemonic Description

7 - 6

P3C1-P3C0

Port 3 Configuration bits (Applicable to P3.0, P3.1, P3.3, P3.4 only)

00 Quasi bi-directional

01 Push-pull

10 Output Low Speed

11 Input with weak pull-up

5-4

Reserved
The value read from these bits are indeterminate. Do not set these bit.

3

CPRESRES

Card Presence Pull-up resistor

Cleared to connect the internal 100K pull-up

Set to disconnect the internal pull-up

2-0

-

Reserved
The value read from these bits are indeterminate. Do not set these bit.

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