PIC17C4X
14.4.2 MINIMIZING CURRENT CONSUMPTION
14.5
Code Protection
To minimize current consumption, all I/O pins should be
either at VDD, or VSS, with no external circuitry drawing
current from the I/O pin. I/O pins that are hi-impedance
inputs should be pulled high or low externally to avoid
switching currents caused by floating inputs. The
T0CKI input should be at VDD or VSS.The contributions
from on-chip pull-ups on PORTB should also be con-
sidered, and disabled when possible.
The code in the program memory can be protected by
selecting the microcontroller in code protected mode
(PM2:PM0 = '000').
Note: PM2 does not exist on the PIC17C42. To
select code protected microcontroller
mode, PM1:PM0 = '00'.
In this mode, instructions that are in the on-chip pro-
gram memory space, can continue to read or write the
program memory. An instruction that is executed out-
side of the internal program memory range will be inhib-
ited from writing to or reading from program memory.
Note: Microchip does not recommend code pro-
tecting windowed devices.
If the code protection bit(s) have not been pro-
grammed, the on-chip program memory can be read
out for verification purposes.
DS30412C-page 106
1996 Microchip Technology Inc.
MICROCHIP [ MICROCHIP ]
