LM3S5D91 Datasheet, PDF (498/1340 Pages) Texas Instruments – Stellaris® LM3S5D91 Microcontroller

External Peripheral Interface (EPI)
Bit/Field
31:24
23
22
21
20
19:16
15:8
Name
reserved
XFFEN
XFEEN
WRHIGH
RDHIGH
reserved
MAXWAIT
Type
RO
R/W
R/W
R/W
R/W
RO
R/W
Reset
0x00
0
Description
Software should not rely on the value of a reserved bit. To provide
compatibility with future products, the value of a reserved bit should be
preserved across a read-modify-write operation.
External FIFO FULL Enable
Value Description
0 No effect.
1 An external FIFO full signal can be used to control write cycles.
If this bit is set and the FFULL signal is high, XFIFO writes are
stalled.
0
External FIFO EMPTY Enable
Value Description
1 An external FIFO empty signal can be used to control read
cycles. If this bit is set and the FEMPTY signal is high, XFIFO
reads are stalled.
0 No effect.
0
WRITE Strobe Polarity
Value Description
0 The WRITE strobe for CS0n is WRn (active Low).
1 The WRITE strobe for CS0n is WR (active High).
0
READ Strobe Polarity
Value Description
0 The READ strobe for CS0n is RDn (active Low).
1 The READ strobe is RD (active High).
0x0
0xFF
Software should not rely on the value of a reserved bit. To provide
compatibility with future products, the value of a reserved bit should be
preserved across a read-modify-write operation.
Maximum Wait
This field defines the maximum number of external clocks to wait while
an external FIFO ready signal is holding off a transaction (FFULL and
FEMPTY).
When this field is clear, the transaction can be held off forever without
a system interrupt.
Note:
When the MODE field is configured to be 0x3 and the BLKEN
bit is set in the EPICFG register, enabling HB16 mode, this
field defaults to 0xFF.
498
January 22, 2012
Texas Instruments-Production Data