27
Appendix A
BASE+27 8254 control, standard mode
Bit
D7
D6
D5
D4
D3
D2
D1
D0
Value
SC1
SC0
RW1
RW0
M2
M1
M0
BCD
Description:
SC1 & SC0Select counter
Counter
SC1
SC0
0
0
0
1
0
1
2
1
0
Read-back command
1
1
RW1 & RW0Select read/write operation
Operation
RW1
RW0
Counter latch
0
0
Read/write LSB
0
1
Read/write MSB
1
0
Read/write LSB first,
1
1
then MSB
M2, M1 & M0Select operating mode
M2
M1
M0
Mode
0
0
0
0 programmable one shot
0
0
1
1 programmable one shot
X
1
0
2 Rate generator
X
1
1
3 Square wave rate generator
1
0
0
4 Software triggered strobe
1
0
1
5 Hardware triggered strobe
BCD Select binary or BCD counting
Summary of Contents for PCI-1751U
Page 1: ...PCI 1751U 48 bit Digital Input Output Card with Universal PCI Bus User Manual ...
Page 5: ...2 CHAPTER 1 General Information ...
Page 9: ...2 CHAPTER 2 Installation ...
Page 15: ...11 Chapter2 2 5 PCI 1751U Block Diagram Figure 2 2 PCI 1751U Block Diagram ...
Page 18: ...PCI 1751U User Manual 14 ...
Page 19: ...2 CHAPTER 3 Operation ...
Page 28: ...PCI 1751U User Manual 24 ...
Page 29: ...2 APPENDIX A Function of 8254 Counter Chip ...