SM320C6455-EP

FIXED-POINT DIGITAL SIGNAL PROCESSOR

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SPRS462B – SEPTEMBER 2007 – REVISED JANUARY 2008

7.21.3 GPIO Electrical Data/Timing

Table 7-114. Timing Requirements for GPIO Inputs(1)(2) (see Figure 7-78)

 

 

 

-720

 

 

 

 

 

-850

 

 

NO.

 

 

A-1000/-1000

UNIT

 

 

 

-1200

 

 

 

 

 

MIN

MAX

 

1

tw(GPIH)

Pulse duration, GPIx high

12P

 

ns

2

tw(GPIL)

Pulse duration, GPIx low

12P

 

ns

(1)P = 1/CPU clock frequency in ns. For example, when running parts at 1000 MHz, use P = 1 ns.

(2)The pulse width given is sufficient to generate a CPU interrupt or an EDMA event. However, if a user wants to have the DSP recognize the GPIx changes through software polling of the GPIO register, the GPIx duration must be extended to at least 24P to allow the DSP enough time to access the GPIO register through the CFGBUS.

Table 7-115. Switching Characteristics Over Recommended Operating Conditions for GPIO Outputs(1)

(see Figure 7-78)

 

 

 

-720

 

 

 

 

-850

 

NO.

 

PARAMETER

A-1000/-1000

UNIT

 

 

 

-1200

 

 

 

 

MIN

MAX

3

tw(GPOH)

Pulse duration, GPOx high

36P – 8(2)

ns

4

tw(GPOL)

Pulse duration, GPOx low

36P – 8(2)

ns

(1)P = 1/CPU clock frequency in ns. For example, when running parts at 1000 MHz, use P = 1 ns.

(2)This parameter value should not be used as a maximum performance specification. Actual performance of back-to-back accesses of the GPIO is dependent upon internal bus activity.

GPIx

GPOx

2

1

4

3

Figure 7-78. GPIO Port Timing

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C64x+ Peripheral Information and Electrical Specifications

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Texas Instruments SM320C6455-EP Gpio Electrical Data/Timing, Timing Requirements for Gpio Inputs12 see Figure, GPIx GPOx