PIC16LC923-04I/L Microchip Technology, PIC16LC923-04I/L Datasheet - Page 47
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PIC16LC923-04I/L
Manufacturer Part Number
PIC16LC923-04I/L
Description
IC,MICROCONTROLLER,8-BIT,PIC CPU,CMOS,LDCC,68PIN,PLASTIC
Manufacturer
Microchip Technology
Series
PIC® 16Cr
Datasheet
1.PIC16C923-04L.pdf
(189 pages)
Specifications of PIC16LC923-04I/L
Rohs Compliant
YES
Core Processor
PIC
Core Size
8-Bit
Speed
4MHz
Connectivity
I²C, SPI
Peripherals
LCD, POR, PWM, WDT
Number Of I /o
25
Program Memory Size
7KB (4K x 14)
Program Memory Type
OTP
Ram Size
176 x 8
Voltage - Supply (vcc/vdd)
2.5 V ~ 6 V
Oscillator Type
External
Operating Temperature
-40°C ~ 85°C
Package / Case
68-PLCC
Processor Series
PIC16LC
Core
PIC
Data Bus Width
8 bit
Data Ram Size
176 B
Interface Type
I2C, SPI
Maximum Clock Frequency
8 MHz
Number Of Programmable I/os
25
Number Of Timers
3
Operating Supply Voltage
2.5 V to 6 V
Maximum Operating Temperature
+ 85 C
Mounting Style
SMD/SMT
3rd Party Development Tools
52715-96, 52716-328, 52717-734
Development Tools By Supplier
ICE2000
Minimum Operating Temperature
- 40 C
Lead Free Status / RoHS Status
Lead free / RoHS Compliant
Eeprom Size
-
Data Converters
-
Lead Free Status / Rohs Status
Details
Available stocks
Company
Part Number
Manufacturer
Quantity
Price
Company:
Part Number:
PIC16LC923-04I/L
Manufacturer:
Microchip Technology
Quantity:
10 000
7.2
When an external clock input is used for Timer0, it must
meet certain requirements. The requirements ensure
the external clock can be synchronized with the internal
phase clock (T
incrementing of Timer0 after synchronization.
7.2.1
When no prescaler is used, the external clock input is
the same as the prescaler output. The synchronization
of T0CKI with the internal phase clocks is accom-
plished by sampling the prescaler output on the Q2 and
Q4 cycles of the internal phase clocks (Figure 7-5).
Therefore, it is necessary for T0CKI to be high for at
least 2Tosc (and a small RC delay of 20 ns) and low for
at least 2Tosc (and a small RC delay of 20 ns). Refer to
the electrical specification of the desired device.
When a prescaler is used, the external clock input is
divided by the asynchronous ripple-counter type pres-
FIGURE 7-5: TIMER0 TIMING WITH EXTERNAL CLOCK
1997 Microchip Technology Inc.
Note 1: Delay from clock input change to Timer0 increment is 3Tosc to 7Tosc. (Duration of Q = Tosc).
Using Timer0 with an External Clock
EXTERNAL CLOCK SYNCHRONIZATION
2: External clock if no prescaler selected, Prescaler output otherwise.
3: The arrows indicate the points in time where sampling occurs.
External Clock/Prescaler
Output after sampling
External Clock Input or
Prescaler output
Therefore, the error in measuring the interval between two edges on Timer0 input = 4Tosc max.
Increment Timer0 (Q4)
OSC
). Also, there is a delay in the actual
(2)
Timer0
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
(3)
(1)
T0
caler so that the prescaler output is symmetrical. For
the external clock to meet the sampling requirement,
the ripple-counter must be taken into account. There-
fore, it is necessary for T0CKI to have a period of at
least 4Tosc (and a small RC delay of 40 ns) divided by
the prescaler value. The only requirement on T0CKI
high and low time is that they do not violate the mini-
mum pulse width requirement of 10 ns. Refer to param-
eters 40, 41 and 42 in the electrical specification of the
desired device.
7.2.2
Since the prescaler output is synchronized with the
internal clocks, there is a small delay from the time the
external clock edge occurs to the time the Timer0 mod-
ule is actually incremented. Figure 7-5 shows the delay
from the external clock edge to the timer incrementing.
TMR0 INCREMENT DELAY
T0 + 1
PIC16C9XX
T0 + 2
DS30444E - page 47
Small pulse
misses sampling