Datasheet

AM1808

SPRS653E –FEBRUARY 2010–REVISED MARCH 2014

www.ti.com

The maximum voltage slew rate for CVdd supply changes is 1 mV/us.

For additional information on power management solutions from TI for this processor, follow the Power

Management link in the Product Folder on www.ti.com for this processor.

The processor supports multiple clock domains some of which have clock ratio requirements to each

other. PLL0_SYSCLK2:PLL0_SYSCLK4:PLL0_SYSCLK6 are synchronous to each other and the

SYSCLKn dividers must always be configured such that the ratio between these domains is 2:4:1. The

ASYNC and ASYNC3 clock domains are asynchronous to the other clock domains and have no specific

ratio requirement.

The table below summarizes the maximum internal clock frequencies at each of the voltage operating

points.

Table 6-5. Maximum Internal Clock Frequencies at Each Voltage Operating Point

CLOCK SOURCE CLOCK DOMAIN 1.3V NOM 1.2V NOM 1.1V NOM 1.0V NOM

PLL0_SYSCLK1 Not used on this processor - - - -

SYSCLK2 clock domain peripherals and optional clock source

PLL0_SYSCLK2 228 MHz 187.5 MHz 100 MHz 50 MHz

for ASYNC3 clock domain peripherals

PLL0_SYSCLK3 Optional clock for ASYNC1 clock domain

PLL0_SYSCLK4 SYSCLK4 domain peripherals 114 MHz 93.75 MHz 50 MHz 25 MHz

PLL0_SYSCLK5 Not used on this processor - - - -

PLL0_SYSCLK6 ARM subsystem 456 MHz 375 MHz 200 MHz 100 MHz

PLL0_SYSCLK7 Optional 50 MHz clock source for EMAC RMII interface 50 MHz 50 MHz - -

DDR2/mDDR Interface clock source (memory interface clock

PLL1_SYSCLK1 312 MHz 312 MHz 300 MHz 266 MHz

is one-half of the value shown)

PLL1_SYSCLK2 Optional clock source for ASYNC3 clock domain peripherals 152 MHz 150 MHz 100 MHz 75 MHz

PLL1_SYSCLK3 Alternate clock source input to PLL Controller 0 75 MHz 75 MHz 75 MHz 75 MHz

McASP AUXCLK Bypass clock source for the McASP 50 MHz 50 MHz 50 MHz 50 MHz

PLL0_AUXCLK Bypass clock source for the USB0 and USB1 48 MHz 48 MHz 48 MHz 48 MHz

Async Mode 148 MHz 148 MHz 75 MHz 50 MHz

ASYNC1 ASYNC1 Clock Domain (EMIFA)

SDRAM Mode 100 MHz 100 MHz 66.6 MHz 50 MHz

ASYNC2 ASYNC2 Clock Domain (multiple peripherals) 50 MHz 50 MHz 50 MHz 50 MHz

Some interfaces have specific limitations on supported modes/speeds at each operating point. See the

corresponding peripheral sections of this document for more information.

TI provides software components (called the Power Manager) to perform DVFS and abstract the task from

the user. The Power Manager controls changing operating points (both frequency and voltage) and

handles the related tasks involved such as informing/controlling peripherals to provide graceful transitions

between operating points.

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Product Folder Links: AM1808