LAN9312-NZW Standard Microsystems (SMSC), LAN9312-NZW Datasheet - Page 108

• Manufacturer Part Number: LAN9312-NZW
• Manufacturer: Standard Microsystems (SMSC)

Specifications of LAN9312-NZW

• Lead Free Status / RoHS Status: Supplier Unconfirmed

Revision 1.7 (06-29-10)
8.4.6
RX Data FIFO Direct PIO Reads
In this mode only A[2] is decoded, and any read of the LAN9312 will read the RX Data FIFO. This
mode is enabled when FIFO_SEL is driven high during a read access. This is normally accomplished
by connecting the FIFO_SEL signal to a high-order address line. This mode is useful when the host
processor must increment its address when accessing the LAN9312.
Timing is identical to a PIO read and the FIFO_SEL and END_SEL signals have the same timing
characteristics as the address lines. An RX Data FIFO direct PIO read cycle begins when both nCS
and nRD are asserted. Either or both of these control signals must de-assert between cycles for the
period specified in
The cycle ends when either or both nCS and nRD are de-asserted. These signals may be asserted
and de-asserted in any order. Read data is valid as indicated in the functional timing diagram in
Figure
Note:
Please refer to
AC timing specifications for RX Data FIFO direct PIO read operations.
D[31:0] (OUTPUT)
Figure 8.5 Functional Timing for RX Data FIFO Direct PIO Read Operation
8.5.
A[9:3] are ignored during RX Data FIFO direct PIO reads.
FIFO_SEL
END_SEL
nCS, nRD
A[x:3]
Section 15.5.6, "RX Data FIFO Direct PIO Read Cycle Timing," on page 447
A[2]
Table 15.10, “RX Data FIFO Direct PIO Read Cycle Timing Values,” on page
(READ DATA FROM RX DATA FIFO)
High Performance Two Port 10/100 Managed Ethernet Switch with 32-Bit Non-PCI CPU Interface
DATASHEET
108
VALID
VALID
VALID
SMSC LAN9312
Datasheet
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447.