Information

PIC16C76
DS80090A-page 4  2001 Microchip Technology Inc.
3. Module: SSP (SPI
TM
Mode Timing
Specifications)
The SPI interface timings (parameters 71, 71A, 72,
72A, 73, and 73A) have been modified. The new
values are shown in Table 4.
TABLE 4: DC SPECIFICATION CHANGES FROM DATA SHEET
4. Module: Timer1
The operation of Timer1 needs some clarification
when the timer registers are written when the
TMR1ON bit is set.
The internal clock signal that is the input to the
TMR1 prescaler affects the incrementing of Timer1
(TMR1H:TMR1L registers and the Timer1 pres-
caler). When the Timer1 registers are NOT written,
the Timer1 will increment on the rising edge of the
TMR1 increment clock.
When the TMR1H and/or TMR1L registers are
written while this clock is high, TMR1 will incre-
ment on the next rising edge of this clock.
When the TMR1H and/or TMR1L registers are
written while this clock is low, TMR1 will not incre-
ment on the next rising edge of this clock, but must
first have a falling clock and the rising clock, for
TMR1 to increment.
Figure 1 shows the two cases of writes to the
TMR1H and/or TMR1L registers. Due to the V
IH
and VIL thresholds on the oscillator/clock pins,
external Timer1 oscillator components, and exter-
nal clock frequency, the Timer1 increment clock
may not be of a 50% duty cycle.
The TMR1 increment clock is out of phase of the
T1OSO/T1CKI pin by a small propagation delay.
FIGURE 1: WRITES TO TIMER1 (EXTERNAL CLOCK/OSCILLATOR MODE)
Param
No.
Sym. Characteristic
New Specification
Data Sheet
Specification
Units
Min Typ Max Min Typ Max
71
T
SCH
SCK input high time
(Slave mode)
Continuous
1.25 T
CY
+ 30 ns
——
T
CY
+ 20 ns
——
ns
71A Single Byte
(1)
40 —— N.A. ns
72
T
SCL
SCK input low time
(Slave mode)
Continuous
1.25 T
CY
+ 30 ns
——
T
CY
+ 20 ns
——
ns
72A Single Byte
(1)
40 —— N.A. ns
73A T
B2B
Last clock edge of the Byte1 to 1st
clock edge of the Byte2
(1)
1.5 TCY
+ 40 ns
—— N.A.
ns
* This parameter is characterized but not tested.
Note 1: Specification 73A is only required if specifications 71A and 72A are used.
TMR1 Increment
Write to TMR1H
TMR1H:TMR1L Increments
Write to TMR1H
TMR1H:TMR1L Increments
Clock (Input to Prescaler)
and/or TMR1L Register(s)
and/or TMR1L Register(s)