MICRF507 datasheet(13/46 Pages) MICREL

13 / 46 page

Micrel, Inc.

MICRF507

March 2010

M9999-032210-B

Reading

Any number of registers with consecutive addresses, from

one up to all 23, can be read.

Procedure:

•

Bring CS active (high). IO is initially an input.

•

Clock in a byte consisting of the address bits and

the R/W bit. The first seven bits are the address

(starting with MSB) of the register, or the first

bit is the R/W bit, which is 1 as this is a read

operation. After the R/W bit is clocked in (falling

edge of SCLK), the next rising edge on SCLK will

enable IO as an output for the duration of the

transaction.

•

Clock out 8 bits per register (one or more) to be

read through IO, MSB first. Rising edges of SCLK

bring each bit to IO. The user can then

conveniently sample the bit at the next falling edge

of SCLK.

•

Bring CS low to end the transaction. IO reverts to

being an input.

Figure 3 shows how to read one register. To read more

registers at consecutive addresses, continue pulsing SCLK

eight times for each register to be read before de-asserting

CS.

Figure 3. Reading a Byte from a Register

Figure 4. Definitions of Control Interface Timing Parameters

MICRF507 Datasheet(PDF) 13 Page - Micrel Semiconductor