Information

 2001 Microchip Technology Inc. DS80061C-page 3
PIC16C773
4. Module: Timer1
When Timer1 is running in Asynchronous mode
and then disabled, data in the Timer1 register
(TMR1) may become corrupted. Corruption occurs
when the timer enable is turned off at the same
instant that a ripple carry occurs in the timer
module.
This issue only occurs in asynchronous operation.
In synchronous operation, the relevant signals are
latched with the CPU clock and the problem condi-
tion does not arise.
Work around
When Timer1 is configured to operate as an asyn-
chronous counter, care must be taken that there is
no incoming pulse while the module is being
turned off. If an incoming pulse arrives while
Timer1 is being turned off, the value of register
TMR1 may become corrupted.
If an application requires that Timer1 be turned off,
and if it is possible that Timer1 may receive an
incoming pulse while being turned off, synchronize
the external clock first by clearing the T1SYNC bit
of register T1CON (T1CON<2>). Please note,
however, that this may cause Timer1 to miss up to
one count.
5. Module: A/D Converter
Exceptions have been observed in the differential
linearity error specification (parameter A04), as
listed in Table 15-9 of the Data Sheet.
No missing codes have been observed when
using up to, and including, 11-bits of resolution. At
12-bits of resolution, up to four missing codes may
occur. The missing codes will never be adjacent.
Work around
None.