User manual

ManualsBrandsTEXAS INSTRUMENTS ManualsDev KitsPCB design board

1161

Enter ISR

Interrupt caused

by ready result in output registers?

[TRNG:IRQFLAGSTAT:RDY]

= 0x1

Read the status register to determine the type of the

granted interrupt value = [TRNG:IRQFLAGSTAT]

Yes No

Read the resulted random number LSW

LSW_result =[TRNG:OUT0]

Read the resulted random number MSW

MSW_result =[TRNG:OUT1]

Clear the result ready event in the status register by

writing to the acknowledge register

[TRNG:IRQFLAGCLR:RDY] = 0x1

Clear alarm events

[TRNG:ALARMMASK:FRO_MASK] = 0x0

[TRNG:ALARMSTOP:FRO_FLAGS] = 0x0

Modify the delay selection in an attempt to prevent

further locking

(detune the particular FRO(s) which had the alarm)

[TRNG:FRODETUNE:FRO_MASK] = 0x-

Re-enable the shut down FROs

[TRNG:FROEN:FRO_MASK] = 0x-

Clear the shutdown overflow event in the status

reguster by writing to the acknowledge register

[TRNG:IRQFLAGCLR:SHUTDOWN_OVF] = 0x1

Exit ISR

Random Number Generator

www.ti.com

16.6.1.3.2 Interrupt Mode

The Interrupt Mode section covers the event servicing of the module. Only the unmonitored mode is

covered. Table 16-4 lists the TRNG interrupt mode steps, while Figure 16-3 shows the interrupt service

routine flow.

Table 16-4. TRNG Interrupt Mode

Step Register / Bit-field Value

Enable interrupt generation when data is ready

[TRNG:IRQFLAGMASK:RDY] 0x1

(available) in the output registers.

Enable the shutdown overflow interrupt generation

when the maximum possible FRO shutdowns reach the [TRNG:IRQFLAGMASK:SHUTDOWN_OVF] 0x1

selected shutdown threshold

Enable the TRNG [TRNG:CTL:TRNG_EN] 0x1

Figure 16-3. Interrupt Service Routine

16.7 Random Number Generator

1162

Random Number Generator SWCU117A–February 2015–Revised March 2015

Submit Documentation Feedback