MCF5253 IntroductionMCF5253 Reference Manual, Rev. 1Freescale Semiconductor 1-91.5.10 ATA ControllerThe ATA block is an AT attachment host interface. Its main use is to interface with IDE hard disc drivesand ATAPI optical disc drives. It interfaces with the ATA device over a number of ATA signals. The ATAinterface is compliant to the ATA-6 standard, and supports PIO mode 0 to 4, multiword DMA mode 0, 1and 2, and ultra DMA mode 0 to 3.1.5.11 Two Controller Area Network (CAN) 2.0B Communication UnitThe two FlexCan modules are full implementation of the Bosch CAN protocol specification 2.0B, whichsupports both standard and extended message frames. The 32 message buffers that are supported, arestored in an embedded RAM.1.5.12 Real-Time ClockThere is an on-chip real-time clock. The real-time clock needs an external 32.768 kHz crystal, and anexternal keep-alive battery. The real-time clock has an anti-tamper feature that will detect when the batteryis removed.1.5.13 Serial Audio InterfacesThe MCF5253 digital audio interface provides three serial Philips IIS/Sony EIAJ interfaces. One interfaceis a 4-pin (1 bit clock, 1 word clock, 1 data in, 1 data out), the other two interfaces are 3-pin (1 bit clock,1 word clock, 1 data in or 1 data out). The serial interfaces have no limit on minimum sampling frequency.Maximum sampling frequency is determined by the maximum frequency on the bit clock input. (1/3 thefrequency of the internal system clock.)1.5.14 IEC958 Digital Audio InterfacesThe MCF5253 has two digital audio input interfaces, and one digital audio output interface. There are fourdigital audio input pins and two digital audio output pins. An internal multiplexer selects one of the fourinputs to one of the two digital audio inputs.One digital audio output carries the consumer “c” channel, the other carries the professional “c” channel.The IEC958 outputs can take the output from the internal IEC958 generator, or multiplex out one of thefour IEC958 inputs.1.5.15 Audio BusThe audio interfaces connect to an internal bus that carries all audio data. Each receiver places its receiveddata on the audio bus and each transmitter takes data from the audio bus for transmission. Each transmitterhas a source select register.In addition to the audio interfaces, there are six CPU accessible registers connected to the audio bus. Threeof these registers allow data reads from the audio bus and allow selection of the audio source. The other
