668-0011 Rabbit Semiconductor, 668-0011 Datasheet - Page 85

• Manufacturer Part Number: 668-0011
• Description: IC MPU RABIT3000A 55.5MHZ128LQFP
• Manufacturer: Rabbit Semiconductor

Specifications of 668-0011

• Rohs Status: RoHS non-compliant
• Processor Type: Rabbit 3000 8-Bit
• Speed: 55.5MHz
• Voltage: 2.5V, 2.7V, 3V, 3.3V
• Mounting Type: Surface Mount
• Package / Case: 128-LQFP
• Features: -
• Other names: 316-1043

10.3 Operation
When PCDR is read, bits 1, 3, 5, and 7 return the logic level on the pin. Bits 0, 2, 4, and 6
return the value of the signal driving the output buffers. The signal driving the output buf-
fers and the value of the output pin are normally the same. The output pins are driven
either by PCDR or by one of the serial port transmit lines. The bits set in the PCFR iden-
tify whether the data register or the serial port transmit lines were driving the pins. When a
parallel port output pin is selected to be a serial port output, the value stored in PCDR is
ignored.
The data line inputs can be set up as asynchronous or clocked serial inputs via bits 4, 5,
and 6 of the corresponding Serial Port Control Registers (SxCR). When serving as serial
inputs, the data lines can still be read from PCDR.
On reset the active (even-numbered) function register bits are zeroed, causing Parallel Port C
to behave as an I/O port. Bit 6 of the Port C data register is zeroed while the remaining
even numbered bits are set to 1.
Chapter 10 Parallel Port C
75