Technical data

NCR - 53C8xx SCSI I/O Processor Tests
http://www.motorola.com/computer/literature 3-77
3
SCRIPTS - SCRIPTs Processor
Command Input
PPCx-Diag>NCR SCRIPTS
Description
This test initializes the test structures and makes use of the diagnostic
registers for test, as follows:
❏ Verifies that the following registers are initially clear:
❏ Sets SCSI outputs in high impedance state, disables interrupts using
the “MIEN”, and sets NCR device for Single Step Mode.
❏ Loads the address of a simple “INTERRUPT instruction” SCRIPT
into the DMA SCRIPTs Pointer register. The SCRIPTs processor is
started by hitting the “STD” bit in the DMA Control Register.
Single Step is checked by verifying that ONLY the first instruction
executed and that the correct status bits are set. Single Step Mode is
then turned off and the SCRIPTs processor started again. The
“INTERRUPT instruction” should then be executed and a check for
the correct status bits set is made.
❏ Loads the address of the “JUMP instruction” SCRIPT into the DMA
SCRIPTs Pointer register, and the SCRIPTs processor is
automatically started. JUMP “if TRUE” (Compare = True,
Compare = False) conditions are checked, then JUMP “if FALSE”
(Compare = True, Compare = False) conditions are checked.
SIEN SCSI Interrupt Enable
DIEN DMA Interrupt Enable
SSTAT0 SCSI Status Zero
DSTAT DMA Status
ISTAT Interrupt Status
SFBR SCSI First Byte Received