8254B CONTROL REGISTER

BADR3 + Bh

WRITE ONLY

7

6

5

4

2

3

1

0

 

 

 

 

 

 

 

 

D7

D6

D5

D4

D3

D2

D1

D0

 

 

 

 

 

 

 

 

The control register is used to set the operating Modes of 8254B Counters 0,1 & 2. A counter is configured by writing the correct Mode information to the Control Register, then the proper count data must be written to the specific Counter Regis- ter.

The Counters on the 8254 are 16-bit devices. Since the interface to the 8254 is only 8-bits wide, Count data is written to the Counter Register as two successive bytes. First the low byte is written, then the high byte. The Control Register is 8-bits

wide. Further information can be obtained on the 8254 data sheet, available from Intel or Harris.

30

Page 33
Image 33
Omega Speaker Systems PCI-DAS1001, PCI-DAS1002 manual 8254B Control Register, BADR3 + Bh