8XC196NT USER’S MANUAL
13-8
Figure 13-4. Typical Voltage on the V
PP
Pin While Exiting Powerdown
Select a resistor that will not interfere with the discharge current. In most cases, values between
200 k
Ω
and 1 M
Ω
should perform satisfactorily. When selecting the capacitor, determine the
worst-case discharge time needed for the oscillator to stabilize, then use this formula to calculate
an appropriate value for C
1
.
where:
C
1
is the capacitor value, in farads
T
DIS
is the worst-case discharge time, in seconds
I
is the discharge current, in amperes
V
t
is the threshold voltage
NOTE
If powerdown is re-entered and exited before C
1
charges to V
CC
, it will take
less time for the voltage to ramp down to the threshold. Therefore, the device
will take less time to exit powerdown.
VPP, Volts
1
2
3
4
5
200
µ
A C1 Discharge
Pullup On
Code Execution Resumes
R1 x C1 Recovery
Time Constant
EXTINT
Time, ms
2
4
6
8
10
12
14
16
18
20
22
A0151-01
C
1
T
DIS
I
×
V
t
--------------------
=
Summary of Contents for 8XC196NT
Page 1: ...8XC196NT Microcontroller User s Manual...
Page 2: ...8XC196NT Microcontroller User s Manual June 1995 Order Number 272317 003...
Page 22: ...1 Guide to This Manual...
Page 23: ......
Page 35: ......
Page 36: ...2 Architectural Overview...
Page 37: ......
Page 49: ......
Page 50: ...3 Programming Considerations...
Page 51: ......
Page 66: ...4 Memory Partitions...
Page 67: ......
Page 104: ...5 Standard and PTS Interrupts...
Page 105: ......
Page 147: ......
Page 148: ...6 I O Ports...
Page 149: ......
Page 176: ...7 Serial I O SIO Port...
Page 177: ......
Page 194: ...8 Synchronous Serial I O SSIO Port...
Page 195: ......
Page 211: ......
Page 212: ...9 Slave Port...
Page 213: ......
Page 231: ......
Page 232: ...10 Event Processor Array EPA...
Page 233: ......
Page 270: ...11 Analog to digital Converter...
Page 271: ......
Page 291: ......
Page 292: ...12 Minimum Hardware Considerations...
Page 293: ......
Page 306: ...13 Special Operating Modes...
Page 307: ......
Page 317: ......
Page 318: ...14 Interfacing with External Memory...
Page 319: ......
Page 362: ...15 Programming the Nonvolatile Memory...
Page 363: ......
Page 408: ...A Instruction Set Reference...
Page 409: ......
Page 476: ...B Signal Descriptions...
Page 477: ......
Page 493: ......
Page 494: ...C Registers...
Page 495: ......
Page 565: ......
Page 566: ...Glossary...
Page 567: ......
Page 580: ...Index...
Page 581: ......
Page 597: ......