iAPX 432 Interface Processor Architecture Reference Manual
Canpleting a block node write transfer which is shorter than the byte count is a
BLOCK moE TERMINATICN
A block node transfer will terminate oormally when all bytes have been transferred, or it may terminate prematurely should a fault occur. In both cases, the IP updates the transfer status attribute and issues an interrupt request to notify the Attached Processor. Following termination, any address reference falling in the subrange of window 0 will cause the windCM to fault and enter the error state. In the error state, requests for data transfer will be will be acknowledged (negatively) by the IP, but 00 data will be
transferred. This prevents a DMA controller, for example, fran continuing to transfer data after a fault has been det;.ected. The faul ted wimow cannot be
The IP tracks the progress of a block transfer by means of an
The IP will terminate a block transfer prematurely if it detects a
fault during the transfer. In addition, the I/O controller may itself force termination before the transfer has been completed. This is done by executing an ALTER MAP AND SELECr DATA SEGMENT function with the transfer status attribute set to "termination forced." Finally, termination may be forced by the IP's receipt of of any the interprocessor conmunication messages "suspend and fully requalify processor", "close windows", or "close windows am enter physical node".