GENERAL DESCRIPTION

The Enhanced SCSI-2 Controller (ESC) was designed to support Fast SCSI-2 transfer rates of up to 10 Mbytes/s in synchronous mode and up to 7 Mbytes/s in the asynchronous mode. The ESC is downward compatible with the Am53C94/96, combining its functionality with features such as Fast SCSI, programmable Active Negation, a 24-bit transfer counter, and a part-unique ID code containing manufacturer and serial # information.

DISTINCTIVE CHARACTERISTICS

■ Pin/function compatible with Emulex FAS216/236

■ AMD’s Patented programmable GLITCH EATERTM Circuitry on REQ and ACK inputs

■ 10 Mbytes/s synchronous Fast SCSI transfer rate

■ 20 Mbytes/s DMA transfer rate

■ 16-Bit DMA interface plus 2 bits of parity

■ Flexible three bus architecture

■ Single-ended SCSI bus supported by Am53CF94

■ Differential SCSI bus supported by Am53CF96

■ Selection of multiplexed or non-multiplexed address and data bus

■ High current drivers (48 mA) for direct connection to the single-ended SCSI bus

■ Supports Disconnect and Reselect commands

■ Supports burst mode DMA operation with a threshold of eight

■ Supports 3-byte tagged-queueing as per the SCSI-2 specification

■ Supports group 2 and 5 command recognition as per the SCSI-2 specification

■ Advanced CMOS process for lower power consumption

■ AMD’s exclusive programmable power-down feature

■ 24-Bit extended transfer counter allows for data block transfer of up to 16 Mbytes

■ Independently programmable 3-byte message and group 2 identification

■ Additional check for ID message during bus-initiated Select with ATN

■ Reselection has QTAG features of ATN3

■ Access FIFO Command

■ Delayed enable signal for differential drivers avoid contention on SCSI differential lines

■ Programmable Active Negation on REQ, ACK and Data lines

■ Register programmable control of assertion/deassertion delay for REQ and ACK lines

■ Part-unique ID code

■ Am53CF94 available in 84-pin PLCC package

■ Am53CF96 available in 100-pin PQFP package

■ Am53CF94 available in 3.3 V version

■ Supports clock operating frequencies from 10 MHz–40 MHz

■ Supports Scatter-Gather or Back-to-Back synchronous data transfers