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PRELIMINARY
DS3 UNI FOR ATM
XRT7245
REV. 1.03
111
process over the Transmit and Receive UTOPIA Data
Buses; as summarized below.
For more information on this parameter, please see
Sections 6.1.2.1.3 and 7.4.2.1.3.
Bits 2, 1,—TFIFODepth[1, 0]
These two “Read/Write” bit-fields allow the user to
configure the Operating Depth of the Tx FIFO; as
summarized below.
Bit 0—UtWidth16—UTOPIA Data Width
This “Read/Write” bit-field allows the user to configure
the width of the UTOPIA Data bus (for both the Transmit
and Receive UTOPIA Interface blocks) to be either 8
bits or 16 bits.
Writing a “0” to this bit-field will configure the UTOPIA
Data bus width (for both Transmit and Receive direc-
tions) to be 8 bits. Writing a “1” to this bit-field will
configure the UTOPIA Data bus width to be 16 bits.
For more information into this option, please see
Section 6.1.2.1.1.
3.3.2.107
Receive UTOPIA Interrupt Enable/Status Register
Bit 6—RxFIFO Reset
This “Read/Write” bit-field allows the user to command
a reset of the RxFIFO, within the Receive UTOPIA
Interface block; without having to command a reset of
the entire chip. Commanding a reset of the RxFIFO
will clear out all of its contents. Additionally, it will
reset the pointer to cells within the RxFIFO. Writing a
“1” to this bit-field will cause the Rx FIFO to be reset.
Bit 5—RxFIFO Overrun Interrupt Enable
This “Read/Write” bit-field allows the user to enable
or disable the “Rx FIFO Overrun Condition” interrupt.
Writing a “0” to this bit-field disables this interrupt.
Writing a “1” to this bit-field enables this interrupt.
Bit 4—RxFIFO Underrun Interrupt Enable
This “Read/Write” bit-field allows the user to enable
or disable the “Rx FIFO Underrun Condition” interrupt.
C
ELL
O
F
52B
YTES
N
UMBER
OF
O
CTETS
PER
C
ELL
0
53 Bytes—When the UTOPIA Data Bus width is configured to be 8 bits
54 Bytes—When the UTOPIA Data Bus width is configured to be 16 bits
1
52 Bytes—Independent of the configured UTOPIA Data bus width
T
X
FIFOD
EPTH
[1, 0]
O
PERATING
D
EPTH
OF
T
X
FIFO
00
16 cells
01
12 cells
10
8 cells
11
4 cells
Address = 6Bh, Receive UTOPIA Interrupt Enable/Status Register
B
IT
7
B
IT
6
B
IT
5
B
IT
4
B
IT
3
B
IT
2
B
IT
1
B
IT
0
Unused
RxFIFO
Reset
RxFIFO
Overflw
Interrupt
Enable
RxFIFO
Underflow
Interrupt
Enable
RCOCA
Interrupt
Enable
RxFIFO
Overflw
Interrupt
Status
RxFIFO
Underflw
Interrupt
Status
RCOCA
Interrupt
Status
RO
R/W
R/W
R/W
R/W
RUR
RUR
RUR
0
0
0
0
0
0
0
0