Motorola TMS320C6711D warranty GENERAL-PURPOSE INPUT/OUTPUT Gpio Port Timing, GPIx GPOx

Models: TMS320C6711D

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SPRS292 − OCTOBER 2005

GENERAL-PURPOSE INPUT/OUTPUT (GPIO) PORT TIMING

timing requirements for GPIO inputs†‡

(see Figure 53)

 

 

 

 

 

 

GDPA−167

 

 

 

 

 

ZDPA−167

 

NO.

 

 

 

−200

 

UNIT

 

 

 

 

−250

 

 

 

 

 

 

MIN

MAX

 

 

 

 

 

 

 

 

1

tw(GPIH)

Pulse duration, GPIx high

 

4P

 

ns

2

tw(GPIL)

Pulse duration, GPIx low

 

4P

 

ns

P = 1/CPU clock frequency in ns. For example, when running parts at 250 MHz, use P = 4 ns.

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.

switching characteristics over recommended operating conditions for GPIO outputs†§ (see Figure 53)

 

 

 

GDPA−167

 

 

 

 

 

ZDPA−167

 

 

NO.

 

PARAMETER

−200

 

UNIT

 

 

 

−250

 

 

 

 

 

MIN

MAX

 

 

 

 

 

 

 

3

tw(GPOH)

Pulse duration, GPOx high

12P − 3

 

ns

4

tw(GPOL)

Pulse duration, GPOx low

12P − 3

 

ns

P = 1/CPU clock frequency in ns. For example, when running parts at 250 MHz, use P = 4 ns.

§The number of CFGBUS cycles between two back-to-back CFGBUS writes to the GPIO register is 12 SYSCLK1 cycles; therefore, the minimum GPOx pulse width is 12P.

GPIx

GPOx

2 1

4

3

Figure 53. GPIO Port Timing

POST OFFICE BOX 1443 HOUSTON, TEXAS 77251−1443

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Motorola TMS320C6711D GENERAL-PURPOSE INPUT/OUTPUT Gpio Port Timing, Timing requirements for Gpio inputs†‡, GPIx GPOx