Chapter 5

Operating Registers

This chapter describes all LSI53C810A operating registers. Table 5.1, the register map, lists registers by operating and configuration addresses. The terms “set” and “assert” are used to refer to bits that are programmed to a binary one. Similarly, the terms “deassert,” “clear,” and “reset” are used to refer to bits that are programmed to a binary zero. Any bits marked as reserved should always be written to zero; mask all information read from them. Reserved bit functions may be changed at any time. Unless otherwise indicated, all bits in registers are active high, that is, the feature is enabled by setting the bit. The bottom row of every register diagram shows the default register values, which are enabled after the chip is powered on or reset.

Note: The only register that the host CPU can access while the LSI53C810A is executing SCRIPTS is the Interrupt Status (ISTAT) register. Attempts to access other registers interferes with the operation of the chip. However, all operating registers are accessible with SCRIPTS. All read data is synchronized and stable when presented to the PCI bus.

The LSI53C810A cannot fetch SCRIPTS instructions from the operating register space. Fetch instructions from system memory.

LSI53C810A PCI to SCSI I/O Processor

5-1

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LSI 53C810A technical manual Chapter Operating Registers