AT43USB325E-AC Atmel, AT43USB325E-AC Datasheet - Page 55

• Manufacturer Part Number: AT43USB325E-AC
• Description: IC USB KEYBOARD CTRLR HUB 64LQFP
• Manufacturer: Atmel
• Series: AVR®r

Specifications of AT43USB325E-AC

• Applications: Keyboard Controller
• Core Processor: AVR
• Program Memory Type: SRAM (16 kB)
• Controller Series: AT43USB
• Ram Size: 512 x 8
• Interface: SPI, 3-Wire Serial
• Number Of I /o: 42
• Voltage - Supply: 4.4 V ~ 5.25 V
• Operating Temperature: 0°C ~ 70°C
• Mounting Type: Surface Mount
• Package / Case: 64-LQFP
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant

7. I/O Ports
3355C–USB–4/05
All GPIO ports have true Read-Modify-Write functionality when used as general digital I/O ports.
This means that the direction of one port pin can be changed without unintentionally changing
the direction of any other pin with the SBI and CBI instructions. The same applies for changing
drive value if configured as output or enabling/disabling of pull-up resistors if configured as input.
The keyboard matrix strobe output pins, PA[0:7], PB[0:7] and PE[0:3] have controlled slope driv-
ers. With a load of 100 pF, the output fall time ranges between 75 ns and 300 ns. The keyboard
matrix strobe input pins, PC[0:7] have When the FE3 IMSK bit is set (1), the Function End-point
3 Interrupt is masked.
PE[4:7] have 5V tolerant outputs and each has a built-in series resistor of 330
These output pins are designed for driving an LED connected to the 5V supply.
The dedicated functions are summarized in
Table 7-1.
In the AT43USB325E Port F[0:3] are used as the SPI signals for the external serial EEPROM.
Once the data from the SEEPROM are loaded to the SRAM, Port F[1:3] become available as
GPIO pins. Only cycling the power to the chip off and on again will temporarily assign these pins
as EEPOM signals.
Function
Scan out[0:7]
Scan out[8:15]
Scan out[16:19]
Scan in[0:7]
LED drivers
EEPROM Interface
GPIO Function Assignments
Table
PA[0:7]
GPIO
PB[0:7]
PE[0:3]
PC[0:7]
PE[4:7]
PF[1:3]
7-1.
AT43USB325
nominal value.
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