Example Of Protocol Using A Serial Eeprom (Xl93Lc66); Read Cycle - Texas Instruments OMAP5912 Reference Manual

Figure 36. Behavior of an XL93LC66 EEPROM Read Cycle
WIRE_NCS
UWIRE_SCLK
1
UWIRESDO
UWIRE_SDI
3.3

Example of Protocol Using a Serial EEPROM (XL93LC66)

3.3.1

Read Cycle

SPRU760B
On the DI line, data is generated from the EEPROM interface on SCLK falling
edge and read by the µWire interface on SCLK falling edge.
1 0 A7 A6 A5 A4 A3 A2 A1 A0
On the DO line, data is generated from the µWire interface on SLCK falling
edge and read by the EEPROM interface on SCLK rising edge.
On the DI line, data is generated from the EEPROM interface on SCLK rising
edge and read by the µWire interface on SCLK rising edge.
Set up the interface by writing the following values in setup 1 register (SR1):
CS_EDGE_RD = 1
-
CS_EDGE_WR = 0
-
CSCS_LVL = 1
-
CS_FRQ = 00
-
CS_CHK = 1
-
In this example, only two cycles (read and write) are described.
1) Set the following fields of the control and status register (CSR):
NB_BITS_RD: 0
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NB_BITS_WR: 0
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INDEX: 00
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CS_CMD: 1
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START: 0
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2) Load the transmit data register (TDR) with:
1 1 0 A7 A6 A5 A4 A3 A2 A1 A0 x x x x x x: Don't care
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A7 ... A0: Address of the selected memory register
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MicroWire Interface
D15 D14 D13 D1 D0
Serial Interfaces 107