W83C553FY-G Nuvoton Technology Corporation of America, W83C553FY-G Datasheet - Page 97

• Manufacturer Part Number: W83C553FY-G
• Manufacturer: Nuvoton Technology Corporation of America

Specifications of W83C553FY-G

• Lead Free Status / RoHS Status: Compliant

W83C553F
Timer Control Register
Function:
Type:
Bit Description:
WINBOND SYSTEMS LABORATORY
Bits [7:6]:
Bits [5:4]:
Bits [3:1]:
Bit 0:
The Timer Control Register specifies the counter selection, operating mode, counter byte programming
order and count value size, and whether the counter counts down in a 16-bit or Binary Coded Decimal
(BCD) format. After writing the control word, a new count can be written at any time. The new value
will take effect according to the programmed mode.
Write Only
SC[1:0]. These bits select the counter the control word acts upon as shown below.
RW[1:0]. These bits are the read/write control bits. Actual counter programming is done
through the counter I/O port (40h, 41h, 42h for counters 0, 1 and 2, respectively).
M[2:0]. These bits select one of six possible modes of operation for the counter as shown
below.
BCD. When this bit is "0", a binary countdown is used. The largest possible binary count is
2 16 . When this bit is "1", a Binary Coded Decimal (BCD) count is used. The largest BCD
count allowed is 10 4 .
Bit 7
Bit 5
Bit 3
0
0
1
1
0
0
1
1
0
0
x
x
1
1
Bit 6
Bit 4
Bit 2
0
1
0
1
0
1
0
1
0
0
1
1
0
0
Function
Counter 0 select
Counter 1 select
Counter 2 select
Read Back command
Function
Counter Latch command
R/W Least Significant Byte (LSB)
R/W Most Significant Byte (MSB)
R/W LSB then MSB
Bit 1
0
1
0
1
0
1
Mode
0
1
2
3
4
5
Function
Out signal on end of count (=0)
Hardware retriggerable one shot
Rate generator (divide by n counter)
Square wave output
Software triggered strobe
Hardware triggered strobe
Electrical Specifications
104