SY10/100E016 Micrel Semiconductor, SY10/100E016 Datasheet - Page 6

• Manufacturer Part Number: SY10/100E016
• Manufacturer: Micrel Semiconductor

Micrel
Programmable Divider
makes it ideal for use as an 8-bit programmable divider. The
TCLD pin (load on terminal count), when asserted, reloads the
data present at the parallel input pin (Pn's) upon reaching
terminal count (an all 1s state on the outputs). Because this
feedback is built internal to the chip, the programmable
division operation will run at very nearly the same frequency
as the maximum counting frequency of the device. Figure 2
below illustrates the input conditions necessary for utilizing
the E016 as a programmable divider set up to divide by 113.
The E016 has been designed with a control pin which
CLOCK
PE
TC
LOAD
H
L
H
Figure 3. Divide by 113 E016 Programmable Divider Waveforms
1001 0000
PE
CE
TCLD
CLK
H
P
Q
Figure 2. Mod 2 to 256 Programmable Divider
7
7
P
Q
L
6
6
1001 0001
P
Q
L
5
5
P
Q
L
4
4
1111 1100
6
Divide by 113
P
H
Q
the desired division, the designer simply subtracts the binary
equivalent of the desired divide ratio for the binary value for
256. As an example for a divide ration of 113:
where
Forcing this input condition, as per the set-up in Figure 2, will
result in the waveforms of Figure 3. Note that the TC output
3
3
To determine what value to load into the device to accomplish
PN's = 256 – 113 = 8F
P
P
0
Q
H
2
2
= LSB and P
P
Q
H
1111 1101
1
1
P
Q
H
0
0
TC
7
= MSB
1111 1110
16
= 1000 1111
1111 1111
LOAD
SY100E016
SY10E016