M42800A Atmel Corporation, M42800A Datasheet - Page 128

• Manufacturer Part Number: M42800A
• Manufacturer: Atmel Corporation

Specifications of M42800A

• Flash (kbytes): 0 Kbytes
• Pin Count: 144
• Max. Operating Frequency: 33 MHz
• Cpu: ARM7TDMI
• Hardware Qtouch Acquisition: No
• Max I/o Pins: 54
• Ext Interrupts: 54
• Usb Speed: No
• Usb Interface: No
• Spi: 2
• Uart: 2
• Graphic Lcd: No
• Video Decoder: No
• Camera Interface: No
• Resistive Touch Screen: No
• Temp. Sensor: No
• Crypto Engine: No
• Sram (kbytes): 8
• Self Program Memory: NO
• External Bus Interface: 1
• Dram Memory: No
• Nand Interface: No
• Picopower: No
• Temp. Range (deg C): -40 to 85
• I/o Supply Class: 3.3/5.0
• Fpu: No
• Mpu / Mmu: no / no
• Timers: 6
• Output Compare Channels: 6
• Input Capture Channels: 6
• 32khz Rtc: Yes
• Calibrated Rc Oscillator: No

128
AT91M42800A
Automatic echo mode allows bit by bit re-transmission. When a bit is received on the RXD line,
it is sent to the TXD line. Programming the transmitter has no effect.
Local loopback mode allows the transmitted characters to be received. TXD and RXD pins are
not used and the output of the transmitter is internally connected to the input of the receiver.
The RXD pin level has no effect and the TXD pin is held high, as in idle state.
Remote loopback mode directly connects the RXD pin to the TXD pin. The Transmitter and
the Receiver are disabled and have no effect. This mode allows bit-by-bit re-transmission.
Figure 17-7. Channel Modes
Remote Loopback
Automatic Echo
Local Loopback
Transmitter
Transmitter
Transmitter
Receiver
Receiver
Receiver
V
DD
Disabled
Disabled
Disabled
Disabled
Disabled
V
DD
RXD
TXD
RXD
TXD
TXD
RXD
1779D–ATARM–14-Apr-06