PIC16F688
For more information, see “MPLAB ICD 2 In-Circuit
Debugger User’s Guide” (DS51292), available on
Microchip’s web site (www.microchip.com).
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.
FIGURE 11-12:
20-Pin PDIP
20-PIN ICD PINOUT
In-Circuit Debug Device
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.
NC
1
2
20
19
18
17
16
15
14
13
12
11
ICDCLK
ICDDATA
ICDMCLR/VPP
VDD
RA5
RA4
3
Vss
RA0
RA1
RA2
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:
4
5
6
RA3
RC5
7
RC0
RC1
RC2
NC
RC4
RC3
ICD
8
9
10
TABLE 11-9: DEBUGGER RESOURCES
Resource
Description
I/O pins
Stack
ICDCLK, ICDDATA
1 level
Program Memory Address 0h must be NOP
700h-7FFh
DS41203B-page 118
Preliminary
2004 Microchip Technology Inc.
MICROCHIP [ MICROCHIP ]
