MR82C54/B Intersil, MR82C54/B Datasheet - Page 13

• Manufacturer Part Number: MR82C54/B
• Manufacturer: Intersil
• Type: Programmabler

Specifications of MR82C54/B

• # Internal Timers: Single
• Propagation Delay Time: 260ns
• Operating Supply Voltage (min): 4.5V
• Operating Supply Voltage (typ): 5V
• Operating Supply Voltage (max): 5.5V
• Package Type: CLCC
• High Level Output Current: -2.5mA
• Low Level Output Current: 2.5mA
• Pin Count: 28
• Operating Temp Range: -55C to 125C
• Operating Temperature Classification: Military
• Mounting: Surface Mount
• Lead Free Status / RoHS Status: Not Compliant

Counter
New counts are loaded and Counters are decremented on
the falling edge of CLK.
The largest possible initial count is 0; this is equivalent to 2
for binary counting and 10
The counter does not stop when it reaches zero. In Modes 0,
1, 4, and 5 the Counter “wraps around” to the highest count,
either FFFF hex for binary counting or 9999 for BCD count-
ing, and continues counting. Modes 2 and 3 are periodic; the
Counter reloads itself with the initial count and continues
counting from there.
STATUS
SIGNAL
MODES
0
1
2
3
4
5
FIGURE 15. GATE PIN OPERATIONS SUMMARY
Disables Counting
1) Disables
2) Sets output im-
1) Disables
2) Sets output im-
1) Disables
GOING LOW
counting
mediately high
counting
mediately high
Counting
LOW OR
-
-
4
1) Initiates
2) Resets output
Initiates Counting Enables Counting
Initiates Counting Enables Counting
Initiates Counting
for BCD counting.
Counting
after next clock
RISING
-
-
Enables Counting
Enables Counting
HIGH
-
-
82C54
16
13
NOTE: 0 is equivalent to 2
FIGURE 16. MINIMUM AND MAXIMUM INITIAL COUNTS
MODE
counting.
0
1
2
3
4
5
16
MIN COUNT
for binary counting and 10
1
1
2
2
1
1
MAX COUNT
0
0
0
0
0
0
4
for BCD