Features
SCSI Interface
| • | Supports TARGET and INITIATOR roles |
| • | Parity generation with optional checking |
| • | Arbitration support |
| • | Direct control/monitoring of all SCSI signals |
| • | High current outputs drive SCSI bus directly |
| • | Faster and improved timing |
| • | Very low SCSI bus loading |
µP Interface
| • | Memory or I/O-mapped control transfers |
| • | Programmed-I/O or DMA data transfers |
| • | Normal or Block-mode DMA |
| • | Fast DMA handshake timing |
Description The DP5380 ASI is a CMOS device designed to provide a low cost, high performance Small Computer Systems Interface. It complies with the ANS X3.131-1986 SCSI standard as defined by the ANSI X3T9.2 committee. It can act as both INITIATOR and TARGET, making it suitable for any application. The ASI supports selection, reselection, arbitration and all other bus phases. High-current open-drain drivers on chip reduce application chip count by interfacing direct to the SCSI bus. An on-chip oscillator provides all timing delays.
The DP5380 is pin and program compatible with the NMOS NCR5380 device. NCR5380 or AM5380 applications can use it with no changes to hardware or software. The DP5380 is available in a 40-pin DIP or a 44-pin PCC.
The ASI is intended to be used in a microprocessor based application, and achieves maximum performance with a DMA controller. The device is controlled by reading and writing several internal registers. A standard non-multiplexed address and data bus easily fits any µP environment.
Data transfers can be performed by programmed-I/O, pseudo-DMA or via a DMA controller. The ASI easily interfaces to a DMA controller using normal or Block Mode. The ASI can be used in either a polled or interrupt-driven environment.
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