參數(shù)資料
型號: MCP2515T-I/ST
元件分類: 微控制器/微處理器
英文描述: 1 CHANNEL(S), 1M bps, SERIAL COMM CONTROLLER, PDSO20
封裝: 4.40 MM, LEAD FREE, PLASTIC, TSSOP-20
文件頁數(shù): 49/88頁
文件大?。?/td> 1205K
代理商: MCP2515T-I/ST
2010 Microchip Technology Inc.
DS21801F-page 53
MCP2515
8.0
OSCILLATOR
The MCP2515 is designed to be operated with a crystal
or ceramic resonator connected to the OSC1 and
OSC2 pins. The MCP2515 oscillator design requires
the use of a parallel cut crystal. Use of a series cut
crystal may give a frequency out of the crystal
manufacturer’s specifications. A typical oscillator circuit
is shown in Figure 8-1. The MCP2515 may also be
driven by an external clock source connected to the
OSC1 pin, as shown in Figure 8-2 and Figure 8-3.
8.1
Oscillator Startup Timer
The MCP2515 utilizes an Oscillator Startup Timer
(OST) that holds the MCP2515 in reset to ensure that
the oscillator has stabilized before the internal state
machine begins to operate. The OST maintains reset
for the first 128 OSC1 clock cycles after power-up or a
wake-up from Sleep mode occurs. It should be noted
that no SPI protocol operations should be attempted
until after the OST has expired.
8.2
CLKOUT Pin
The CLKOUT pin is provided to the system designer for
use as the main system clock or as a clock input for
other devices in the system. The CLKOUT has an inter-
nal prescaler which can divide FOSC by 1, 2, 4 and 8.
The CLKOUT function is enabled and the prescaler is
selected
via
the
CANCNTRL
register
(see
The CLKOUT pin will be active upon system reset and
default to the slowest speed (divide by 8) so that it can
be used as the MCU clock.
When Sleep mode is requested, the MCP2515 will
drive sixteen additional clock cycles on the CLKOUT
pin before entering Sleep mode. The idle state of the
CLKOUT pin in Sleep mode is low. When the CLKOUT
function is disabled (CANCNTRL.CLKEN = ‘0’) the
CLKOUT pin is in a high-impedance state.
The CLKOUT function is designed to ensure that
thCLKOUT and tlCLKOUT timings are preserved when the
CLKOUT pin function is enabled, disabled or the
prescaler value is changed.
FIGURE 8-1:
CRYSTAL/CERAMIC RESONATOR OPERATION
FIGURE 8-2:
EXTERNAL CLOCK SOURCE
Note:
The maximum frequency on CLKOUT is
specified as 25 MHz (See Table 13-5)
C1
C2
XTAL
OSC2
RS(1)
OSC1
RF(2)
SLEEP
To internal logic
Note 1: A series resistor (RS) may be required for AT strip cut crystals.
2: The feedback resistor (RF ), is typically in the range of 2 to 10 M
Ω.
Clock from
external system
OSC1
OSC2
Open
(1)
Note 1: A resistor to ground may be used to reduce system noise. This may increase system current.
2: Duty cycle restrictions must be observed (see Table 12-1).
相關(guān)PDF資料
PDF描述
MCP79400-I/MNY REAL TIME CLOCK, PDSO8
MCP79400T-I/ST REAL TIME CLOCK, PDSO8
MCP79402-I/MS REAL TIME CLOCK, PDSO8
MCP79401T-I/SN REAL TIME CLOCK, PDSO8
MCP79400T-I/SN REAL TIME CLOCK, PDSO8
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
MCP2551 制造商:MICROCHIP 制造商全稱:Microchip Technology 功能描述:High-Speed CAN Transceiver
MCP2551_07 制造商:MICROCHIP 制造商全稱:Microchip Technology 功能描述:High-Speed CAN Transceiver
MCP2551_10 制造商:MICROCHIP 制造商全稱:Microchip Technology 功能描述:High-Speed CAN Transceiver
MCP2551A-E/P 功能描述:CAN 接口集成電路 Enhanced HI SPD CAN Transceiver RoHS:否 制造商:Texas Instruments 類型:Transceivers 工作電源電壓:5 V 電源電流: 工作溫度范圍:- 40 C to + 85 C 封裝 / 箱體:SOIC-8 封裝:Tube
MCP2551A-E/SN 功能描述:CAN 接口集成電路 Enhanced HI SPD CAN Transceiver RoHS:否 制造商:Texas Instruments 類型:Transceivers 工作電源電壓:5 V 電源電流: 工作溫度范圍:- 40 C to + 85 C 封裝 / 箱體:SOIC-8 封裝:Tube