TWI General Operation
11-10
ADSP-BF537 Blackfin Processor Hardware Reference
Fast Mode
Fast mode essentially uses the same mechanics as standard mode of opera-
tion. It is the electrical specifications and timing that are most effected.
When fast mode is enabled (
FAST
) the following timings are modified to
meet the electrical requirements.
• Serial data rise times before arbitration evaluation (t
r
)
• Stop condition set-up time from serial clock to serial data
(t
SU;STO
)
• Bus free time between a stop and start condition (t
BUF
)
TWI General Operation
The following sections describe the general operation of the TWI.
TWI Control
The TWI control register (
TWI_CONTROL
) is used to enable the TWI mod-
ule as well as to establish a relationship between the system clock (
SCLK
)
and the TWI controller’s internally timed events. The internal time refer-
ence is derived from
SCLK
using a prescaled value.
PRESCALE
=
f
SCLK
/
10MHz
SCCB compatibility is an optional feature and should not be used in an
I
2
C bus system. This feature is turned on by setting the
SCCB
bit in the
TWI_CONTROL
register. When this feature is set all slave asserted acknowl-
edgement bits are ignored by this master. This feature is valid only during
transfers where the TWI is mastering an SCCB bus. Slave mode transfers
should be avoided when this feature is enabled because the TWI controller
always generates an acknowledge in slave mode.
Summary of Contents for Blackfin ADSP-BF537
Page 42: ...Contents xlii ADSP BF537 Blackfin Processor Hardware Reference ...
Page 90: ...Development Tools 1 32 ADSP BF537 Blackfin Processor Hardware Reference ...
Page 138: ...Programming Examples 4 26 ADSP BF537 Blackfin Processor Hardware Reference ...
Page 340: ...SDC Programming Examples 6 84 ADSP BF537 Blackfin Processor Hardware Reference ...
Page 606: ...Programming Examples 9 94 ADSP BF537 Blackfin Processor Hardware Reference ...
Page 660: ...Programming Examples 10 54 ADSP BF537 Blackfin Processor Hardware Reference ...
Page 720: ...Electrical Specifications 11 60 ADSP BF537 Blackfin Processor Hardware Reference ...
Page 840: ...Programming Examples 13 42 ADSP BF537 Blackfin Processor Hardware Reference ...
Page 876: ...Programming Examples 14 36 ADSP BF537 Blackfin Processor Hardware Reference ...
Page 938: ...Programming Examples 15 62 ADSP BF537 Blackfin Processor Hardware Reference ...
Page 958: ...Programming Examples 17 12 ADSP BF537 Blackfin Processor Hardware Reference ...
Page 986: ...Programming Examples 18 28 ADSP BF537 Blackfin Processor Hardware Reference ...
Page 1162: ...G 26 ADSP BF537 Blackfin Processor Hardware Reference ...
Page 1218: ...Index I 56 ADSP BF537 Blackfin Processor Hardware Reference ...