
W83977EF/ CTF
PRELIMINARY
Publication Release Date: March 1999
-73 -
Revision A1
Bit 5-3: Reflect the IRQ resource assigned for ECP port.
cnfgB[5:3]
000
001
010
011
100
101
110
111
IRQ resource
reflect other IRQ resources selected by PnP register (default)
IRQ7
IRQ9
IRQ10
IRQ11
IRQ14
IRQ15
IRQ5
Bit 2-0: These five bits are at high level during a read and can be written
.
5.3.10 ecr (Extended Control Register) Mode = all
This register controls the extended ECP parallel port functions. The bit definitions are follows:
7 6 5 4 3 2 1 0
empty
full
service Intr
dmaEn
nErrIntrEn
MODE
MODE
MODE
Bit 7-5: These bits are read/write and select the mode.
000
Standard Parallel Port mode. The FIFO is reset in this mode.
001
PS/2 Parallel Port mode. This is the same as 000 except that direction may be
used to tri-state the data lines, and reading the data register returns the value on
the data lines and not the value in the data register.
010
Parallel Port FIFO mode. This is the same as 000 except that bytes are written or
DMAed to the FIFO. FIFO data are automatically transmitted using the standard
parallel port protocol. This mode is useful only when direction is 0.
011
ECP Parallel Port Mode. When the direction is 0 (forward direction), bytes placed
into the ecpDFifo and bytes written to the ecpAFifo are placed in a single FIFO and
auto transmitted to the peripheral using ECP Protocol. When the direction is 1
(reverse direction), bytes are moved from the ECP parallel port and packed into
bytes in the ecpDFifo.
100
Selects EPP Mode. In this mode, EPP is activated if the EPP mode is selected.
101
Reserved.
110
Test Mode. The FIFO may be written and read in this mode, but the data will not be
transmitted on the parallel port.