Interface Overview
16-4
ADSP-BF50x Blackfin Processor Hardware Reference
Serial Clock Signal (SCL)
In slave mode this signal is an input and an external master is responsible
for providing the clock.
In master mode the TWI controller must set this signal to the desired fre-
quency. The TWI controller supports the standard mode of operation (up
to 100 KHz) or fast mode (up to 400 KHz).
The TWI control register (
TWI_CONTROL
) is used to set the
PRESCALE
value
which gives the relationship between the system clock (
SCLK
) and the TWI
controller’s internally timed events. The internal time reference is derived
from
SCLK
using a prescaled value.
PRESCALE
= f
SCLK
/10MHz
The
PRESCALE
value is the number of system clock (
SCLK
) periods used in
the generation of one internal time reference. The value of
PRESCALE
must
be set to create an internal time reference with a period of 10 MHz. It is
represented as a 7-bit binary value.
It is not always possible to achieve 10 MHz accuracy. In such cases,
it is safe to round up the
PRESCALE
value to the next highest integer.
For example, if
SCLK
is 133 MHz, the
PRESCALE
value is calculated
as 133 MHz/10 MHz = 13.3. In this case, a
PRESCALE
value of 14
ensures that all timing requirements are met.
Serial Data Signal (SDA)
This is a bidirectional signal on which serial data is transmitted or received
depending on the direction of the transfer.
Summary of Contents for EZ-KIT Lite ADSP-BF506F
Page 50: ...Contents l ADSP BF50x Blackfin Processor Hardware Reference ...
Page 92: ...Development Tools 1 30 ADSP BF50x Blackfin Processor Hardware Reference ...
Page 110: ...Interface Overview 3 12 ADSP BF50x Blackfin Processor Hardware Reference ...
Page 236: ...Internal Flash Memory Control Registers 6 92 ADSP BF50x Blackfin Processor Hardware Reference ...
Page 650: ...Programming Examples 15 56 ADSP BF50x Blackfin Processor Hardware Reference ...
Page 804: ...Programming Examples 17 92 ADSP BF50x Blackfin Processor Hardware Reference ...
Page 1194: ...Programming Examples 24 90 ADSP BF50x Blackfin Processor Hardware Reference ...
Page 1256: ...ACM Registers A 50 ADSP BF50x Blackfin Processor Hardware Reference ...
Page 1264: ...Boundary Scan Architecture B 8 ADSP BF50x Blackfin Processor Hardware Reference ...