DP83905AVQB National Semiconductor, DP83905AVQB Datasheet - Page 68

• Manufacturer Part Number: DP83905AVQB
• Description: IC CONTROLR AT/LAN TP IN 160PQFP
• Manufacturer: National Semiconductor
• Series: AT/LANTIC™r

Specifications of DP83905AVQB

• Controller Type: AT, LAN Twisted-Pair Interface Controller
• Voltage - Supply: 4.75 V ~ 5.25 V
• Current - Supply: 100mA
• Operating Temperature: 0°C ~ 70°C
• Mounting Type: Surface Mount
• Package / Case: 160-BFQFP
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Interface: -
• Other names: *DP83905AVQB

6 0 Operation of AT LANTIC Controller
RAM Access Timing
This is a memory read cycle executed by the AT LANTIC Controller’s internal DMA This is used to either load the data transfer
port during a Remote Read in I O mode or to load the FIFO for a transmission on the network in both modes This transfer is
synchronized to BSCLK which can be either driven from the 20 MHz input on X1 or by the BSCLK input This is selected by the
CLKSEL bit in Configuration Register C If there is 8 kbytes of RAM only RCS1 is used if 16 kbytes are available RCS1 and
RCS2 are used
This is a memory write cycle executed by the AT LANTIC Controller’s internal DMA This is used to either write from the data
transfer port during a Remote Write in I O mode or to empty the FIFO during a reception from the network in both modes This
transfer is synchronized to BSCLK which can be either driven from the 20 MHz input on X1 or by the BSCLK input This is
selected by the CLKSEL bit in Configuration Register C If there is 8 kbytes of RAM only RCS1 is used if 16 kbytes are available
RCS1 and RCS2 are used
Memory Support Write
Memory Support Read
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TL F 11498 – 51
TL F 11498 – 52