PIC16F688 Datasheet, PDF (120/174 Pages) Microchip Technology – 14-Pin Flash-Based, 8-Bit CMOS Microcontrollers with nanoWatt Technology

PIC16F688
11.12 In-Circuit Debugger
Since in-circuit debugging requires access to the data
and MCLR pins, MPLAB^® ICD 2 development with an
14-pin device is not practical. A special 20-pin
PIC16F688 ICD device is used with MPLAB ICD 2 to
provide separate clock, data and MCLR pins and frees
all normally available pins to the user.
A special debugging adapter allows the ICD device to
be used in place of a PIC16F688 device. The
debugging adapter is the only source of the ICD device.
When the ICD pin on the PIC16F688 ICD device is held
low, the In-Circuit Debugger functionality is enabled.
This function allows simple debugging functions when
used with MPLAB ICD 2. When the microcontroller has
this feature enabled, some of the resources are not
available for general use. Table 11-9 shows which
features are consumed by the background debugger:
TABLE 11-9: DEBUGGER RESOURCES
Resource
Description
I/O pins
Stack
Program Memory
ICDCLK, ICDDATA
1 level
Address 0h must be NOP
700h-7FFh
For more information, see “MPLAB ICD 2 In-Circuit
Debugger User’s Guide” (DS51292), available on
Microchip’s web site (www.microchip.com).
FIGURE 11-12: 20-PIN ICD PINOUT
20-Pin PDIP
In-Circuit Debug Device
NC
ICDMCLR/VPP
VDD
RA5
RA4
RA3
RC5
RC4
RC3
ICD
1 20
2 ₁₉
3 ₁₈
4 17
5 ₁₆
6 15
7 ₁₄
8 13
9 ₁₂
10 11
ICDCLK
ICDDATA
Vss
RA0
RA1
RA2
RC0
RC1
RC2
NC
DS41203B-page 118
Preliminary
 2004 Microchip Technology Inc.