ADSP-BF50x Blackfin Processor Hardware Reference
8-23
Dynamic Power Management
The external clock select (
EXTCLK_SEL
) control bit configures the
EXTCLK
pin to output either the SCLK frequency (called
CLKOUT
) or to output an
input buffered CLKIN frequency (called
CLKBUF
). When configured to
output SCLK (
CLKOUT
), the
EXTCLK
pin acts as a reference signal in many
timing specifications. While CLKOUT is active by default, it can be dis-
abled using the
EBIU_AMGCTL
register. When configured to output CLKIN
(
CLKBUF
), the
EXTCLK
pin allows another device
and
the Blackfin processor
to run from a single crystal oscillator.
The external clock output enable (
EXTCLK_OE
) control bit configures the
EXTCLK
pin to
either
enable (when set, =1)
or
disable (when cleared, =0) the
output of the clock signal selected by
EXTCLK_SEL
. When
EXTCLK_OE
is
cleared, the
EXTCLK
pin is three-stated.
The
POLARITY
control bit configure the active level of the wakeup event on
the programmable flags. Note that the CAN RX wakeup event is always
active low and is
not
affected by the
POLARITY
bit.
System Control ROM Function
The PLL and voltage regulator registers should not be accessed directly.
Instead, use the
bfrom_SysControl()
function to alter or read the register
values. The function resides in the on-chip ROM and can be called by the
user following C-language style calling conventions.
Entry address: 0xEF00 0038
Arguments:
•
dActionFlags
word in
R0
•
pSysCtrlSettings
pointer in
R1
• zero value in
R2
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 ...