lm2502sm National Semiconductor Corporation, lm2502sm Datasheet - Page 13

• Manufacturer Part Number: lm2502sm
• Description: Mobile Pixel Link Mpl Display Interface Serializer And Deserializer
• Manufacturer: National Semiconductor Corporation

Functional Description
fourth section the MD lines are again turned around, such
that the Master becomes the transmitter and the Slave be-
comes the receiver. The Slave drives the MD lines Low for 1
bit width and then turns off. The MD lines are off momentarily
to avoid driver contention. The Master then drives the MD
line Low for 1 bit time and then idles the bus until the next
transaction is sent.
To account for the latency through the MPL link, a dual
READ operation is required by the host. The first read re-
turns invalid data (all Low). Once data has returned to the
Master LM2502, the INTR signal is asserted to inform the
Figure 11 illustrates a m68 mode WRITE followed by a
READ operation (Slave output to Display). At the end of the
WRITE operation the SLAVE outputs are turned off. The
FIGURE 11. Slave WRITE and Slave READ m68 mode Operation
(Continued)
FIGURE 10. READ_Data and TA”
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During a READ transaction (Double Read access on the
Master), other MPL transactions are not allowed until the
current READ dual cycle is completed.
host to initiate a second read operation. When the Master
LM2502 sees the Read signal/CS* combination, it will de-
assert the INTR signal and Valid data is presented.
SLAVE latches in the READ data on the rising edge of the
CS* signal as shown. The Display should disable its outputs
prior to the next operation to avoid any bus contention.
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