Interphase Tech 4221 Network Card User Manual


 
Chapter 1 - Introduction
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interrupt handler outputs an interrupt vector number for the non-DMA engine interrupts or requests access to the LBUS
for a DMA engine IACK cycles.
CPU/LBUS Interface
The CPU/LBUS Interface links the CPU core with the LBUS resources. The CPU/LBUS interface converts the CPU
Core bus to the LBUS. The Interface is a one-way interface which allows the CPU to act as a LBUS master. The
interface does not allow other LBUS masters to access the CPU Core.
The CPU/LBUS interface is composed of address latches, data-latching transceivers, and control logic. The
CPU/LBUS Interface performs write-posting and read-latching to maximize the CPU bus and the LBUS performance.
The interface also performs relinquish retries, read-modify-write cycles, IACK cycles to the DMA engine,
back-to-back write-write cycles and back-to-back, write-read cycles.