LM2502 datasheet(9/27 Pages) NSC

9 / 27 page

Functional Description

BUS OVERVIEW

The LM2502 is a dual link Transceiver configurable part that

supports a 16-bit CPU (m68 or i80) style interface. The MPL

physical layer is purpose-built for an extremely low power

and low EMI data transmission while requiring the fewest

number of signal lines. No external line components are

required, as termination is provided internal to the MPL

receiver. A maximum raw throughput of 307 Mbps (raw) is

possible with this chipset. When the protocol overhead is

taken into account, a maximum data throughput of 245 Mbps

is possible. The MPL interface is designed for use with

common 50

Ω to 100Ω lines using standard materials and

connectors. Lines may be microstrip or stripline construction.

Total length of the interconnect is expected to be less than

20cm.

SERIAL BUS TIMING

Data valid is relative to both edges for a WRITE as shown in

Figure 4. Data valid is specified as: Data Valid before Clock,

Data Valid after Clock, and Skew between data lines should

be less than 500ps.

Data is strobed out on the rising edge by the Slave for a

READ as shown in Figure 5. The Master monitors for the

start bit transition (Low to High) and selects the best strobe

to sample the incoming data on. This is done to account for

the round trip delay of the interconnect and application data

rate.

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FIGURE 3. MPL Point-to-Point Bus

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FIGURE 4. Dual Link Timing (WRITE)

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FIGURE 5. Dual Link Timing (READ)

LM2502 Datasheet(PDF) 9 Page - National Semiconductor (TI)