參數(shù)資料
型號(hào): KSZ8873MLLJ
廠商: Micrel Inc
文件頁數(shù): 10/108頁
文件大?。?/td> 0K
描述: IC ETHERNET SWITCH 3PORT 64LQFP
特色產(chǎn)品: KSZ8873MLLJ Ethernet Switches
標(biāo)準(zhǔn)包裝: 160
系列: *
其它名稱: 576-3996
2008 Microchip Technology Inc.
DS39631E-page 105
PIC18F2420/2520/4420/4520
10.0
I/O PORTS
Depending on the device selected and features
enabled, there are up to five ports available. Some pins
of the I/O ports are multiplexed with an alternate
function from the peripheral features on the device. In
general, when a peripheral is enabled, that pin may not
be used as a general purpose I/O pin.
Each port has three registers for its operation. These
registers are:
TRIS register (Data Direction register)
PORT register (reads the levels on the pins of the
device)
LAT register (Data Latch register)
The Data Latch (LAT register) is useful for read-modify-
write operations on the value that the I/O pins are
driving.
A simplified model of a generic I/O port, without the
interfaces to other peripherals, is shown in Figure 10-1.
FIGURE 10-1:
GENERIC I/O PORT
OPERATION
10.1
PORTA, TRISA and LATA Registers
PORTA is an 8-bit wide, bidirectional port. The corre-
sponding Data Direction register is TRISA. Setting a
TRISA bit (= 1) will make the corresponding PORTA pin
an input (i.e., put the corresponding output driver in a
high-impedance mode). Clearing a TRISA bit (= 0) will
make the corresponding PORTA pin an output (i.e., put
the contents of the output latch on the selected pin).
Reading the PORTA register reads the status of the
pins, whereas writing to it, will write to the port latch.
The Data Latch (LATA) register is also memory mapped.
Read-modify-write operations on the LATA register read
and write the latched output value for PORTA.
The RA4 pin is multiplexed with the Timer0 module
clock input and one of the comparator outputs to
become the RA4/T0CKI/C1OUT pin. Pins RA6 and
RA7 are multiplexed with the main oscillator pins; they
are enabled as oscillator or I/O pins by the selection of
the main oscillator in the Configuration register (see
for details). When
they are not used as port pins, RA6 and RA7 and their
associated TRIS and LAT bits are read as ‘0’.
The other PORTA pins are multiplexed with analog
inputs, the analog VREF+ and VREF- inputs and the com-
parator voltage reference output. The operation of pins
RA<3:0> and RA5 as A/D Converter inputs is selected
by clearing or setting the control bits in the ADCON1
register (A/D Control Register 1).
Pins RA0 through RA5 may also be used as comparator
inputs or outputs by setting the appropriate bits in the
CMCON register. To use RA<3:0> as digital inputs, it is
also necessary to turn off the comparators.
The RA4/T0CKI/C1OUT pin is a Schmitt Trigger input.
All other PORTA pins have TTL input levels and full
CMOS output drivers.
The TRISA register controls the direction of the PORTA
pins, even when they are being used as analog inputs.
The user must ensure the bits in the TRISA register are
maintained set when using them as analog inputs.
EXAMPLE 10-1:
INITIALIZING PORTA
Data
Bus
WR LAT
WR TRIS
RD Port
Data Latch
TRIS Latch
RD TRIS
Input
Buffer
I/O pin(1)
Q
D
CK
Q
D
CK
EN
QD
EN
RD LAT
or Port
Note 1:
I/O pins have diode protection to VDD and VSS.
Note:
On a Power-on Reset, RA5 and RA<3:0>
are configured as analog inputs and read
as ‘0’. RA4 is configured as a digital input.
CLRF
PORTA
; Initialize PORTA by
; clearing output
; data latches
CLRF
LATA
; Alternate method
; to clear output
; data latches
MOVLW
07h
; Configure A/D
MOVWF
ADCON1
; for digital inputs
MOVWF
07h
; Configure comparators
MOVWF
CMCON
; for digital input
MOVLW
0CFh
; Value used to
; initialize data
; direction
MOVWF
TRISA
; Set RA<3:0> as inputs
; RA<5:4> as outputs
相關(guān)PDF資料
PDF描述
KSZ8873MMLI IC ETHERNET SWITCH 3PORT 64LQFP
KSZ8893FQL IC SWITCH FAST ETH 3PORT 128PQFP
KSZ8895MQI IC ETHERNET SWITCH 5PORT 128PQFP
KSZ8895MQ IC ETHERNET SW 5PORT 128-PQFP
KSZ8993FL IC CONV MED 10/100 SGL 128PQFP
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
KSZ8873MML 功能描述:以太網(wǎng) IC 3-Port Fast Ethernet Switch with 2x MII Interface, Lead Free RoHS:否 制造商:Micrel 產(chǎn)品:Ethernet Switches 收發(fā)器數(shù)量:2 數(shù)據(jù)速率:10 Mb/s, 100 Mb/s 電源電壓-最大:1.25 V, 3.45 V 電源電壓-最小:1.15 V, 3.15 V 最大工作溫度:+ 85 C 封裝 / 箱體:QFN-64 封裝:Tray
KSZ8873MML-EVAL 功能描述:以太網(wǎng)開發(fā)工具 3-Port Fast Ethernet Switch with 2x MII Interface - Evaluation Board RoHS:否 制造商:Micrel 產(chǎn)品:Evaluation Boards 類型:Ethernet Transceivers 工具用于評(píng)估:KSZ8873RLL 接口類型:RMII 工作電源電壓:
KSZ8873MMLI 功能描述:以太網(wǎng) IC 3-Port Fast Ethernet Switch with 2x MII Interface (Industrial Grade) RoHS:否 制造商:Micrel 產(chǎn)品:Ethernet Switches 收發(fā)器數(shù)量:2 數(shù)據(jù)速率:10 Mb/s, 100 Mb/s 電源電壓-最大:1.25 V, 3.45 V 電源電壓-最小:1.15 V, 3.15 V 最大工作溫度:+ 85 C 封裝 / 箱體:QFN-64 封裝:Tray
KSZ8873RLL 功能描述:以太網(wǎng) IC 3-Port Fast Ethernet Switch with 1x RMII Interface, Lead Free RoHS:否 制造商:Micrel 產(chǎn)品:Ethernet Switches 收發(fā)器數(shù)量:2 數(shù)據(jù)速率:10 Mb/s, 100 Mb/s 電源電壓-最大:1.25 V, 3.45 V 電源電壓-最小:1.15 V, 3.15 V 最大工作溫度:+ 85 C 封裝 / 箱體:QFN-64 封裝:Tray
KSZ8873RLL-EVAL 功能描述:以太網(wǎng)開發(fā)工具 3-Port Fast Ethernet Switch with 1x RMII Interface - Evalaution Board RoHS:否 制造商:Micrel 產(chǎn)品:Evaluation Boards 類型:Ethernet Transceivers 工具用于評(píng)估:KSZ8873RLL 接口類型:RMII 工作電源電壓: