18F2520 PLL
Добавлено: Чт апр 09, 2015 13:55:16
Как так пишут в даташите??
Или я чего то не понимаю?
The PLL is only available to the crystal oscillator when
the FOSC<3:0> Configuration bits are programmed for
HSPLL mode (= 0110).
А потом
The 4x frequency multiplier can be used with the inter-
nal oscillator block to produce faster device clock
speeds than are normally possible with an internal
oscillator. When enabled, the PLL produces a clock
speed of up to 32 MHz.
Unlike HSPLL mode, the PLL is controlled through
software. The control bit, PLLEN (OSCTUNE<6>), is
used to enable or disable its operation.
The PLL is available when the device is configured to
use the internal oscillator block as its primary clock
source (FOSC<3:0> = 1001 or 1000). Additionally, the
PLL will only function when the selected output fre-
quency is either 4 MHz or 8 MHz (OSCCON<6:4> = 111
or 110). If both of these conditions are not met, the PLL
is disabled.
The PLLEN control bit is only functional in those inter-
nal oscillator modes where the PLL is available. In all
other modes, it is forced to ‘0’ and is effectively
unavailable.
В итоге я бьюь час так и не смог 32 мгц сделать.. Это возможно??
И будет нормально usart на 19200 работать??
У меня нет кварца, включен внутренний генератор FOSC 1001.
PLL включен, OSCCON<6:4> = 111 и нифига. 8мгц хоть тресни
Или я чего то не понимаю?
The PLL is only available to the crystal oscillator when
the FOSC<3:0> Configuration bits are programmed for
HSPLL mode (= 0110).
А потом
Спойлер
2.6.4 PLL IN INTOSC MODESThe 4x frequency multiplier can be used with the inter-
nal oscillator block to produce faster device clock
speeds than are normally possible with an internal
oscillator. When enabled, the PLL produces a clock
speed of up to 32 MHz.
Unlike HSPLL mode, the PLL is controlled through
software. The control bit, PLLEN (OSCTUNE<6>), is
used to enable or disable its operation.
The PLL is available when the device is configured to
use the internal oscillator block as its primary clock
source (FOSC<3:0> = 1001 or 1000). Additionally, the
PLL will only function when the selected output fre-
quency is either 4 MHz or 8 MHz (OSCCON<6:4> = 111
or 110). If both of these conditions are not met, the PLL
is disabled.
The PLLEN control bit is only functional in those inter-
nal oscillator modes where the PLL is available. In all
other modes, it is forced to ‘0’ and is effectively
unavailable.
В итоге я бьюь час так и не смог 32 мгц сделать.. Это возможно??
И будет нормально usart на 19200 работать??
У меня нет кварца, включен внутренний генератор FOSC 1001.
PLL включен, OSCCON<6:4> = 111 и нифига. 8мгц хоть тресни
