STWBC2-HP datasheet(68/96 Pages) STMICROELECTRONICS

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Figure 68. Single byte read access

2.2.13.3.3

Multiple byte write access with address auto-increment:

The auto-increment is activated with a specific signal of the I/F.

The first byte transmitted by the master after NSS goes low corresponds to the initial access address. The MSB of

this byte is 0, meaning that it is a write access. During the transmission of the first byte, the slave transmits 8bits

data at 0.

The second byte sent by the master is the 8bits data to be written at the requested address. While the data

byte to be written is sent by the master, the slave transmits the value at address+1. This offers the possibility to

combine a write and read on adjacent address.

For each following byte, the address of the access is automatically incremented up to 0x7F. When 0x7F is

reached, the address is no more incremented.

The write process stops when NSS comes high.

Figure 69. Multiple byte write with address auto-increment

2.2.13.3.4

Multiple byte write access at fixed address:

The auto-increment is deactivated with a specific signal of the I/F.

The first byte transmitted by the master after NSS goes low corresponds to the initial access address. The MSB of

this byte is 0, meaning that it is a write access. During the transmission of the first byte, the slave transmits 8bits

data at 0.

The second byte sent by the master is the 8bits data to be written at the requested address. While the data

byte to be written is sent by the master, the slave transmits the value at address+1. This offers the possibility to

combine a write and read on adjacent address.

For each following byte, the address of the access is the same. This mode of operation fits perfectly with a FIFO

fill operation.

The write process stops when NSS comes high.

Figure 70. Multiple byte write with fixed address

2.2.13.3.5

Multiple byte read access with explicit addresses:

The first byte transmitted by the master after NSS goes low corresponds to the first access address. The MSB of

this byte is 1, meaning that it is a read access. During the transmission of the first byte, the slave transmits 8bits

data at 0.

Each following byte transmitted by the master corresponds to a new address on which the read has to be done.

These bytes must have their MSB bit at 1. During the transmission of the new address, the slave responds to the

data read at the previous address request.

The read process stops when NSS comes high.

STWBC2-HP

Digital AFE functions

DS13825 - Rev 1.0

page 68/96

STWBC2-HP Datasheet(PDF) 68 Page - STMicroelectronics