6-12 User’s Manual

6.4.7 Parallel Port Operation Mode

The parallel port supports four operation modes:
• Standard and Bidirectional
• Extended Capabilities Port(ECP)
• Standard and Unidirectional
• Enhanced Parallel Port(EPP)
ECP or Extended Capabilities Port supports a 16-byte FIFO (first in, first
out) which can be accessed by host DMA cycles and PIO cycles. ECP
boosts I/O bandwidth to meet the demands of high-performance
peripherals. EPP or Enhanced Parallel Port is a parallel port interface that
greatly improves performance for bi-directional block-mode data transfers.
EPP provides greater throughput by supporting faster transfer times and a
mechanism that allows the host to address peripheral device registers
directly.
The default setting is [Standard and Bidirectional].
If you set EPP as the parallel port operation mode, do not use
3BCh as the parallel port base address; otherwise, I/O conflicts
may occur.
ECP DMA Channel
Set the ECP DMA Channel parameter if you set the Parallel Port Operation
Mode to [Enhanced Capabilities Port(ECP)]. The default
value, with ECP selected, is [0].