Texas Instruments SM320C6455-EP manual Static Powerdown Reset Enable Progress Disabled Enabled

Models: SM320C6455-EP

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SM320C6455-EP

FIXED-POINT DIGITAL SIGNAL PROCESSOR

www.ti.com

SPRS462B – SEPTEMBER 2007 – REVISED JANUARY 2008

Static

Powerdown

Reset

Enable In

Progress

Disabled

Enabled

Figure 3-1. Peripheral Transitions Between States

Figure 3-2shows the flow needed to change the state of a given peripheral on the C6455 device.

Unlock the PERCFG0 register by

using the PERLOCK register.

Write to the PERCFG0 register within 16 SYSCLK3 clock cycles

to change the state of the

peripherals.

Poll the PERSTAT registers to

verify state change.

Figure 3-2. Peripheral State Change Flow

A 32 bit key (value = 0x0F0A 0B00) must be written to the Peripheral Lock register (PERLOCK) in order to allow access to the PERCFG0 register. Writes to the PERCFG1 register can be done directly without going through the PERLOCK register.

NOTE

The instructions that write to the PERLOCK and PERCFG0 registers must be in the same fetch packet if code is being executed from external memory. If the instructions are in different fetch packets, fetching the second instruction from external memory may stall the instruction long enough such that PERCFG0 register will be locked before the instruction is executed.

64

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Page 64
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Texas Instruments SM320C6455-EP manual Static Powerdown Reset Enable Progress Disabled Enabled