beautypg.com

2 interrupt timing – Texas Instruments TMS3320C5515 User Manual

Page 55

background image

www.ti.com

Interrupts

The interrupt flag register (IFR1) and interrupt enable register 1 (IER1) bit layouts are shown in

Figure 1-26

and described in

Table 1-34

.

Figure 1-26. IFR1 and IER1 Bit Locations

15

11

10

9

8

Reserved

RTOS

DLOG

BERR

R-0

R/W-0

R/W-0

R/W-0

7

6

5

4

3

2

1

0

I2C

EMIF

GPIO

USB

SPI

RTC

RCV3

XMT3

R/W-0

R/W-0

R/W-0

R/W-0

R/W-0

R/W-0

R/W-0

R/W-0

LEGEND: R/W = Read/Write; R = Read only; -n = value after reset

Table 1-34. IFR1 and IER1 Bit Descriptions

Bit

Field

Value

Description

15-11

Reserved

0

Reserved. This bit should always be written with 0.

10

RTOS

1-0

Real-Time operating system interrupt flag/mask bit.

9

DLOG

1-0

Data log interrupt flag/mask bit.

8

BERR

1-0

Bus error interrupt flag/mask bit.

7

I2C

1-0

I2C interrupt flag/mask bit.

6

EMIF

1-0

EMIF error interrupt flag/mask bit.

5

GPIO

1-0

GPIO aggregated interrupt flag/mask bit.

4

USB

1-0

USB interrupt flag/mask bit.

3

SPI

1-0

SPI interrupt flag/mask bit.

2

RTC

1-0

Wakeup or real-time clock interrupt flag/mask bit.

1

RCV3

1-0

I2S3 receive interrupt flag/mask bit.

0

XMT3

1-0

I2S3 transmit interrupt flag/mask bit.

1.6.2 Interrupt Timing

The interrupt signals on the external interrupts pins (INT0 and INT1) are detected with a synchronous
negative edge detector circuit. To reliably detect the external interrupts, the interrupt signal must have at
least 2 SYSCLK high followed by at least 2 SYSCLK low.

To define the minimum low pulse width in nanoseconds scale, you should take into account that the
on-chip PLL of the device is software programmable and that your application may be dynamically
changing the frequency of PLL. You should use the slowest frequency that will be used by your application
to calculate the minimum interrupt pulse duration in nanoseconds.

When the system master clock is disabled (SYSCLKDIS =1), the external interrupt pins (INT0 and INT1)
will be asynchronously latched and held low while the clocks are re-enabled. Once the clocks are
re-enabled, the DSP will latch the interrupt in the IFR.

55

SPRUFX5A – October 2010 – Revised November 2010

System Control

Submit Documentation Feedback

Copyright © 2010, Texas Instruments Incorporated