Datasheet

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TMS320C6472
www.ti.com SPRS612G–JUNE 2009– REVISED JULY 2011
Table 7-18. PLL1 Clock Frequency Ranges
REQUIRED FREQUENCY REQUIRED FREQUENCY REQUIRED FREQUENCY
CLOCK SIGNAL UNIT
FOR 500-MHz OPERATION FOR 625-MHz OPERATION FOR 700-MHz OPERATION
CLKIN1 15.625 - 50.0 19.531 - 50.0 21.875 - 50.0 MHz
SYSCLK1 500.0 625.0 700.0 MHz
SYSCLK2 500.0 625.0 700.0 MHz
SYSCLK3 500.0 625.0 700.0 MHz
SYSCLK4 500.0 625.0 700.0 MHz
SYSCLK5 500.0 625.0 700.0 MHz
SYSCLK6 500.0 625.0 700.0 MHz
SYSCLK7 166.7 208.4 233.3 MHz
SYSCLK8 83.3 104.1 116.7 MHz
SYSCLK9 250.0 312.5 350.0 MHz
SYSCLK10 166.7
(1)
208.4
(1)
233.3
(1)
MHz
(1) This frequency may be changed by reprogramming SYSCLK10.
7.8.1.2 PLL1 Controller Operating Modes
The PLL1 controller has two modes of operation: bypass mode and PLL mode. The mode of operation is
determined by the PLLEN bit of the PLL control register (PLLCTL). In PLL mode, SYSREFCLK is
generated from the device input clock, CLKIN1, using the the PLL multiplier, PLLM. In bypass mode,
CLKIN1 is fed directly to SYSREFCLK. All hosts (HPI, etc.) must hold off accesses to the DSP while the
frequency of its internal clocks is changing. A mechanism must be in place such that the DSP notifies the
host when the PLL configuration has completed.
The PLL3 controller provides the control to reset PLL3. It is also capable of placing it in a power-down
condition for systems where DDR2 EMIF is not being used.
7.8.1.3 PLL1 Stabilization, Lock, and Reset Times
The PLL stabilization time is the amount of time that must be allotted for the internal PLL regulators to
become stable after device powerup. The PLL output should not be used until this stabilization time has
expired. The PLL reset time is the amount of wait time needed when resetting the PLL (writing PLLRST =
1), in order for the PLL to properly reset, before bringing the PLL out of reset (writing PLLRST = 0). For
the PLL1 reset time value, see Table 7-19.The PLL lock time is the amount of time needed from when the
PLL is taken out of reset (PLLRST = 1 with PLLEN = 0) to when the PLL controller can be switched to PLL
mode (PLLEN=1). The PLL1 lock time is given in Table 7-19.
Table 7-19. PLL1 Stabilization, Lock, and Reset Times
MIN TYP MAX UNIT
PLL1 stabilization time 50 μs
PLL1 lock time 2000 * C
(1)
ns
PLL1 reset time 256 * C
(1)
ns
(1) C = CLKIN1 cycle time in ns. For example, when CLKIN1 frequency is 50 MHz, use C = 20 ns.
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