
PORT 2C DATA
BADR2 + 06h
READ/WRITE
CL0CL1CL2CL3CH0CH1CH2CH3
01234567
CONTROL REGISTER 2
BADR2 + 07h
WRITE only
D0D1-D3D4---
01234567
See BADR2 + 03h and Table 5-2 for a description of the Control Register.
COUNTER 1 DATA
BADR2 + 08h
READ/WRITE
D0D1D2D3D4D5D6D7
01234567
COUNTER 2 DATA
BADR2 + 09h
READ/WRITE
D0D1D2D3D4D5D6D7
01234567
COUNTER 3 DATA
BADR2 + 0Ah
READ/WRITE
D0D1D2D3D4D5D6D7
01234567
CONTROL REGISTER COUNTERS 1 - 3
BADR2 + 0Bh
WRITE ONLY
D0D1D2D3D4D5D6D7
01234567
The control register is used to set the operating Modes of 8254 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 Register.
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.
10
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