Specifications

System Macros Invoked by Drivers
SPI$SEND_BYTES
SPI$SEND_BYTES
Sends command, message, and data bytes to a device acting as an initiator on the
SCSI bus.
Format
SPI$SEND_BYTES
Description
The SPI$SEND_BYTES macro allows the host to send information to the device
acting as an initiator. A class driver uses SPI$SEND_BYTES to send command,
message, and data bytes. This macro uses DMA operations for the transfer of
large segments of data where appropriate.
Inputs to the SPI$SEND_BYTES macro include the following:
Location Contents
R0 Size of the system buffer that contains the bytes to be sent
R1 Address of the system buffer that contains the bytes to be
sent
R4 Address of the SPDT
The port driver returns the following values to the class driver, destroying R2,
and preserving all other registers:
Location Contents
R0 Port status. The port driver returns one of the following
values:
SS$_NORMAL Normal, successful completion.
SS$_CTRLERR Timeout occurred during the
operation.
R1 Actual number of bytes sent.
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