
SMSC DS – FDC37N958FR
Page 118
Rev. 09/01/99
This bit shall be set to 1 whenever there are
writeIntrThreshold or more bytes free in the FIFO.
case dmaEn=0 direction=1:
This bit shall be set to 1 whenever there are
readIntrThreshold or more valid bytes to be read
from the FIFO.
BIT 1 full
Read only
1:
The FIFO cannot accept another byte or the
FIFO is completely full.
0:
The FIFO has at least 1 free byte.
BIT 0 empty
Read only
1:
The FIFO is completely empty.
0:
The FIFO contains at least 1 byte of data.
Table 49 - Extended Control Register
R/W
000:
MODE
Standard Parallel Port Mode . In this mode the FIFO is reset and common collector
drivers are used on the control lines (nStrobe, nAutoFd, nInit and nSelectIn). Setting
the direction bit will not tri-state the output drivers in this mode.
PS/2 Parallel Port Mode. Same as above 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. All drivers have active pull-ups (push-pull).
Parallel Port FIFO Mode. This is the same as 000 except that bytes are written or
DMAed to the FIFO. FIFO data is automatically transmitted using the standard parallel
port protocol. Note that this mode is only useful when direction is 0. All drivers have
active pull-ups (push-pull).
ECP Parallel Port Mode. In the forward direction (direction is 0) bytes placed into the
ecpDFifo and bytes written to the ecpAFifo are placed in a single FIFO and transmitted
automatically to the peripheral using ECP Protocol. In the reverse direction (direction is
1) bytes are moved from the ECP parallel port and packed into bytes in the ecpDFifo.
All drivers have active pull-ups (push-pull).
Selects EPP Mode: In this mode, EPP is selected if the EPP supported option is
selected in configuration register L3-CRF0. All drivers have active pull-ups (push-pull).
Reserved
Test Mode. In this mode the FIFO may be written and read, but the data will not be
transmitted on the parallel port. All drivers have active pull-ups (push-pull).
Configuration Mode. In this mode the confgA, confgB registers are accessible at 0x400
and 0x401. All drivers have active pull-ups (push-pull).
001:
010:
011:
100:
101:
110:
111: