BIT 4 nErrIntrEn
Read/Write (Valid only in ECP Mode)
1: Disables the interrupt generated on the asserting edge of nFault.
0: Enables an interrupt pulse on the high to low edge of nFault. Note that an interrupt will be generated if nFault is
asserted (interrupting) and this bit is written from a 1 to a 0. This prevents interrupts from being lost in the time
between the read of the ecr and the write of the ecr.
SMSC DS – LPC47M192
Page 94
Rev. 03/30/05
DATASHEET
BIT 3 dmaEn
Read/Write
1: Enables DMA (DMA starts when serviceIntr is 0).
0: Disables DMA unconditionally.
BIT 2 serviceIntr
Read/Write
1: Disables DMA and all of the service interrupts.
0: Enables one of the following 3 cases of interrupts. Once one of the 3 service interrupts has occurred
serviceIntr bit shall be set to a 1 by hardware. It must be reset to 0 to re-enable the interrupts. Writing this bit to a
1 will not cause an interrupt.
case dmaEn=1:
During DMA (this bit is set to a 1 when terminal count is reached).
case dmaEn=0 direction=0:
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 44a - Extended Control Register
R/W
000:
MODE
Standard Parallel Port Mode . In this mode the FIFO is reset and common drain 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: