at89c5131 ATMEL Corporation, at89c5131 Datasheet - Page 9

• Manufacturer Part Number: at89c5131
• Description: 8-bit Flash Microcontroller With Full Speed Usb Device At89c5131
• Manufacturer: ATMEL Corporation

4136C–USB–04/05
Table 8. Ports Signal Description
Table 9. Clock Signal Description
Table 10. USB Signal Description
Signal
Signal
Signal
Name
Name
XTAL1
XTAL2
P0[7:0]
P1[7:0]
P2[7:0]
P3[7:0]
P4[1:0]
Name
VREF
PLLF
D+
D-
Type
Type
Type
I/O
I/O
O
O
I/O
I/O
I/O
I/O
I/O
I
I
Description
Input to the on-chip inverting oscillator amplifier
To use the internal oscillator, a crystal/resonator circuit is connected to this
pin. If an external oscillator is used, its output is connected to this pin.
Output of the on-chip inverting oscillator amplifier
To use the internal oscillator, a crystal/resonator circuit is connected to this
pin. If an external oscillator is used, leave XTAL2 unconnected.
PLL Low Pass Filter input
Receives the RC network of the PLL low pass filter.
Description
USB Data + signal
USB Data - signal
USB Reference Voltage
Connect this pin to D+ using a 1.5 kΩ resistor to use the Detach function.
Description
Port 0
P0 is an 8-bit open-drain bidirectional I/O port. Port 0
pins that have 1s written to them float and can be used
as high impedance inputs. To avoid any parasitic current
consumption, Floating P0 inputs must be pulled to V
V
Port 1
P1 is an 8-bit bidirectional I/O port with internal pull-ups.
Port 2
P2 is an 8-bit bidirectional I/O port with internal pull-ups.
Port 3
P3 is an 8-bit bidirectional I/O port with internal pull-ups.
Port 4
P4 is an 2-bit open port.
SS
.
DD
or
AT89C5131
Alternate Function
CEX[4:0]
LED[3:0]
KIN[7:0]
AD[7:0]
A[15:8]
T2EX
INT0
INT1
RxD
SCL
SDA
TxD
ECI
WR
RD
T2
T0
T1
Alternate
Alternate
Function
Function
-
-
-
-
-
-
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