Table 13-1 PIO Pin Assignments and Register Bits

PIO No.

Register Bit

 

 

Associated Pin

Power-On Reset Status

 

 

 

 

“0” Registers (PIOMODE0, 70h; PDIR0, 72h; PDATA0, 74h)

 

 

 

 

 

 

0

0

 

 

TMRIN1

Input with pullup

 

 

 

 

 

 

1

1

 

 

TMROUT1

Input with pulldown

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

2

2

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Input with pullup

 

PCS6/A2

3

3

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Input with pullup

 

PCS5/A1

4

4

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Normal operation(3)

 

DT/R

5

5

 

 

 

 

 

 

 

 

 

 

 

 

 

Normal operation(3)

 

DEN

6

6

 

 

SRDY

Normal operation(4)

7(1)

7

 

 

A17

Normal operation(3)

8(1)

8

 

 

A18

Normal operation(3)

9(1)

9

 

 

A19

Normal operation(3)

10

10

 

 

TMROUT0

Input with pulldown

 

 

 

 

 

 

11

11

 

 

TMRIN0

Input with pullup

 

 

 

 

 

 

12

12

 

 

DRQ0

Input with pullup

 

 

 

 

 

 

13

13

 

 

DRQ1

Input with pullup

 

 

 

 

 

 

 

 

 

 

 

 

 

 

14

14

 

 

 

 

 

 

 

 

 

 

 

 

 

Input with pullup

 

MCS0

15

15

 

 

 

 

 

 

 

 

 

 

 

 

 

Input with pullup

MCS1

“1” Registers (PIOMODE1, 76h; PDIR0, 78h; PDATA0, 7Ah)

 

 

 

 

 

 

 

 

 

 

 

 

 

 

16

0

 

 

 

 

 

 

 

 

 

 

 

Input with pullup

 

PCS0

17

1

 

 

 

 

 

 

 

 

 

 

 

Input with pullup

PCS1

18

2

 

 

 

 

 

 

 

 

 

 

 

Input with pullup

PCS2

19

3

 

 

 

 

 

 

 

 

 

 

 

Input with pullup

PCS3

20

4

 

 

SCLK

Input with pullup

 

 

 

 

 

 

21

5

 

 

SDATA

Input with pullup

 

 

 

 

 

 

22

6

 

 

SDEN0

Input with pulldown

 

 

 

 

 

 

23

7

 

 

SDEN1

Input with pulldown

 

 

 

 

 

 

 

 

 

 

 

 

 

 

24

8

 

 

 

 

 

 

 

 

 

 

 

 

 

Input with pullup

 

MCS2

25

9

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Input with pullup

 

MCS3/RFSH

26(1,2)

10

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Input with pullup

 

UZI/CLKSEL2

27

11

 

 

TXD

Input with pullup

 

 

 

 

 

 

28

12

 

 

RXD

Input with pullup

 

 

 

 

 

 

 

29(1,2)

13

 

 

 

 

 

 

 

 

 

 

 

 

Input with pullup

 

S6/CLKSEL1

30

14

 

 

INT4

Input with pullup

 

 

 

 

 

 

31

15

 

 

INT2

Input with pullup

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Notes:

1.These pins are used by emulators. (Emulators also use S2–S0, RES, NMI, CLKOUTA, BHE, ALE, AD15–AD0, and A16–A0.)

2.These pins revert to normal operation if BHE/ADEN (Am186ER) or RFSH2/ADEN (Am188ER) is held Low during power-on reset.

3.When used as a PIO, input with pullup option available.

4.When used as a PIO, input with pulldown option available.

13-2

Programmable I/O Pins

Page 166
Image 166
AMD Am186TMER, Am188TMER user manual Registers PIOMODE1, 76h PDIR0, 78h PDATA0, 7Ah, 13-2