SI2438FT18-EVB Silicon Laboratories Inc, SI2438FT18-EVB Datasheet - Page 49

• Manufacturer Part Number: SI2438FT18-EVB
• Description: BOARD EVAL SI2438+SI3018 24PIN
• Manufacturer: Silicon Laboratories Inc

Specifications of SI2438FT18-EVB

• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

In Figure 37 the CID field is 0. As this field is decremented in LSB to MSB order, the value decrements for each SDI
down the line. The BRCT and R/W bits remain unchanged as the control word passes through the entire chain. A
unique CID is presented to each device, and the device receiving a CID value of 0 is the target of the operation
(channel 0 in this case). Figure 38 illustrates that in broadcast mode, all bits pass through the chain without
permutation.
Figure 39 and Figure 40 illustrate WRITE and READ operations via an 8-bit SPI controller. Each of these
operations are performed as a 3-byte transfer. The CS pin is asserted between each byte. The CS pin must be
asserted before the first falling edge of SCLK after the DATA byte to indicate to the state machine that only one
byte should be transferred. The state of the SDI pin is ignored during the DATA byte of a read operation.
CS B
S CLK
S DI
S DO
SDI0-15
CS B
S CLK
S DI
S DO
CSB
SCLK
SDI
SDO
Figure 38. Sample SPI Control Byte for Broadcast Mode (Write Only)
CONTROL
CONTROL
1
CONTROL
Figure 39. Write Operation via an 8-bit SPI Port
Figure 40. Read Operation via an 8-bit SPI Port
Figure 41. Write Operation via a 16-bit SPI Port
0
A DDRE S S
1
A DDRE S S
Rev. 1.4
ADDRESS
0
Si3050 + Si3011/18/19
Data [7:0]
X
DA TA [7:0]
XXXXXXXXXXXX
X
X X X X X X X X
Data [7:0]
X
Hi-Z
X
Hi - Z
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