TMPR3901F

4.4.2INT[5:0]*

The INT[5:0]* signals are used to invoke interrupt exceptions. These interrupts can be masked with the IntMask field of the Status register. The TMPR3901F recognizes an INT[5:0]* signal on the SYSCLK rising edge (Figure 4-7).

1

2

SYSCLK

INT[5:0]*

Figure 4-7 Interrupt

1Recognize INT[5:0]* high signal.

2Recognize INT[5:0]* low signal, thus invoking interrupt exception.

The TMPR3901F recognizes an INT[5:0]* low signal on the SYSCLK rising edge as shown Figure 4-

7.The INT[5:0]* signal must be kept low until the interrupt exception occurs. If the signal is asserted and then de-asserted before a SYSCLK rising edge occurs, the interrupt will not be recognized and the exception will not be invoked.

Furthermore, the interrupt handler in order to determine which of the INI[5:0]* interrupts has occurred must read the status register IP field that shows the status of the INT[5:0]* signals. Therefore, the signal invoking the interrupt must be held low until the exception occurs and the interrupt handler has been invoked and has determined the source of the interrupt.

The INT[5:0]* signal should be de-asserted by the interrupt handler.If the signal remains asserted, the interrupt will reoccur as soon as the handler reenables interrupts.

226

Page 237
Image 237
Toshiba TX39 user manual 2 INT50, Interrupt