The 82355 incorporates two independent state machine to control the transfer protocol of the EISA interface and the Transfer Buffer Interface (TBI). During a transfer, the current transfer byte count information is only available to the EISA interface state machine. The EISA interface state machine is responsible for signaling the Transfer Buffer Interface's state machine to stop reading/writing when the terminal count is reached. The EISA interface will stop with the last byte (word or double word) of transfer.
During EISA READ's, the TBI state machine receives the "STOP" signal from the EISA interface state machine while transferring data out of the 82355 internal 24-byte FIFO. The "STOP" signal is synchronized with the last word to be transferred and the TBI state machine turns off with the last word transfer.
During EISA WRITE's, the TBI state machine receives the "STOP" signal after it has read data beyond the number of bytes specified (overreads by a maximum of 28 bytes). The overread bytes are flushed from the BMIC's internal FIFO when the next transfer is initiated.