LAN9116 datasheet(95/109 Pages) MICROCHIP

95 / 109 page

 2005-2016 Microchip Technology Inc.

DS00002268A-page 95

LAN9116

6.5

RX Data FIFO Direct PIO Burst Reads

In this mode the upper address inputs are not decoded, and any burst read of the LAN9116 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 LAN9116. Timing is identical to a PIO Burst Read, and the FIFO_SEL signal has the same

timing characteristics as the address lines. In this mode, performance is improved by allowing an unlimited number of

back-to-back DWORD or WORD read cycles. RX Data FIFO Direct PIO Burst Reads can be performed using Chip

Select (nCS) or Read Enable (nRD). When either or both of these control signals go high, they must remain high for the

period specified.

Timing for 16-bit and 32-bit RX Data FIFO Direct PIO Burst Reads is identical with the exception that D[31:16] are not

driven during a 16-bit burst. Note that address lines A[2:1] are still used, and address bits A[7:3] are ignored.

FIGURE 6-4:

RX DATA FIFO DIRECT PIO BURST READ CYCLE TIMING

Note:

The “Data Bus” width is 32 bits with optional support for 16-bit bus widths.

FIGURE 6-5:

RX DATA FIFO DIRECT PIO BURST READ CYCLE TIMING

Symbol

Description

MIN

TYP

MAX

Units

tcsh

nCS, nRD Deassertion Time

tcsdv

nCS, nRD Valid to Data Valid

tacyc

Address Cycle Time

165

tasu

Address, FIFO_SEL Setup to nCS, nRD Valid

tadv

Address Stable to Data Valid

tah

Address, FIFO_SEL Hold Time

tdon

Data Buffer Turn On Time

tdoff

Data Buffer Turn Off Time

tdoh

Data Output Hold Time

Note:

An RX Data FIFO Direct PIO Burst Read cycle begins when both nCS and nRD are asserted. The cycle

ends when either or both nCS and nRD are deasserted. They may be asserted and deasserted in any

order.

Data Bus

nCS, nRD

FIFO_SEL

A[2:1]

LAN9116 Datasheet(PDF) 95 Page - Microchip Technology

LAN9116 Datasheet(HTML) 95 Page - Microchip Technology

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 ...More

Datasheet Download

Link URL