
ADSP-BF59x Blackfin Processor Hardware Reference
9-3
Core Timer
Internal Interfaces
The core timer is accessed through the 32-bit register access bus (RAB).
The module is clocked by the core clock
CCLK
. The timer’s dedicated inter-
rupt request is a higher priority than requests from all other peripherals.
Description of Operation
The software should initialize the
TCOUNT
register
before
the timer is
enabled. The
TCOUNT
register can be written directly, but writes to the
TPERIOD
register are also passed through to
TCOUNT
.
When the timer is enabled by setting the
TMREN
bit in the core timer con-
trol register (
TCNTL
), the
TCOUNT
register is decremented once every time
the prescaler
TSCALE
expires, that is, every
TSCALE
+ 1 number of
CCLK
clock cycles. When the value of the
TCOUNT
register reaches 0, an interrupt
is generated and the
TINT
bit is set in the
TCNTL
register.
If the
TAUTORLD
bit in the
TCNTL
register is set, then the
TCOUNT
register is
reloaded with the contents of the
TPERIOD
register and the count begins
again. If the
TAUTORLD
bit is not set, the timer stops operation.
The core timer can be put into low power mode by clearing the
TMPWR
bit
in the
TCNTL
register. Before using the timer, set the
TMPWR
bit. This
restores clocks to the timer unit. When
TMPWR
is set, the core timer may
then be enabled by setting the
TMREN
bit in the
TCNTL
register.
Hardware behavior is undefined if
TMREN
is set when
TMPWR
=
0
.
Interrupt Processing
The timer’s dedicated interrupt request is a higher priority than requests
from all other peripherals. The request goes directly to the core event
controller (CEC) and does not pass through the system interrupt
Содержание ADSP-BF59x Blackfin
Страница 64: ...Development Tools 1 22 ADSP BF59x Blackfin Processor Hardware Reference...
Страница 74: ...Processor Specific MMRs 2 10 ADSP BF59x Blackfin Processor Hardware Reference...
Страница 204: ...Unique Information for the ADSP BF59x Processor 5 104 ADSP BF59x Blackfin Processor Hardware Reference...
Страница 244: ...Programming Examples 6 40 ADSP BF59x Blackfin Processor Hardware Reference...
Страница 345: ...ADSP BF59x Blackfin Processor Hardware Reference 9 9 Core Timer Unique Information for the ADSP BF59x Processor None...
Страница 346: ...Unique Information for the ADSP BF59x Processor 9 10 ADSP BF59x Blackfin Processor Hardware Reference...
Страница 398: ...Unique Information for the ADSP BF59x Processor 11 42 ADSP BF59x Blackfin Processor Hardware Reference...
Страница 622: ...Unique Information for the ADSP BF59x Processor 15 38 ADSP BF59x Blackfin Processor Hardware Reference...
Страница 700: ...Programming Examples 16 78 ADSP BF59x Blackfin Processor Hardware Reference...
Страница 738: ...Boundary Scan Architecture B 8 ADSP BF59x Blackfin Processor Hardware Reference...