16F648 datasheet(115/180 Pages) MICROCHIP

115 / 180 page

DS40044G-page 115

PIC16F627A/628A/648A

14.13 In-Circuit Debugger

Since in-circuit debugging requires the loss of clock,

data and MCLR pins, MPLAB® ICD 2 development with

an 18-pin device is not practical. A special 28-pin

PIC16F648A-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. Debugging of all

three versions of the PIC16F627A/628A/648A is

supported by the PIC16F648A-ICD.

This special ICD device is mounted on the top of a

header and its signals are routed to the MPLAB ICD 2

connector. On the bottom of the header is an 18-pin

socket that plugs into the user’s target via an 18-pin

stand-off connector.

When the ICD pin on the PIC16F648A-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 14-19

shows which features are consumed by the background

debugger.

TABLE 14-19: DEBUGGER RESOURCES

The PIC16F648A-ICD device with header is supplied

as an assembly. See Microchip Part Number

AC162053.

I/O pins

ICDCLK, ICDDATA

Stack

1 level

Program Memory

Address 0h must be NOP

300h-3FEh

16F648 Datasheet(PDF) 115 Page - Microchip Technology