Interrupt Requests - Toshiba TMPR4937 Manual

15.3.7

Interrupt requests

It is possible to make interrupt requests to external devices and interrupt requests (IRC interrupts) to
the TX49/H3 core by using a 16-bit interrupt request flag register. REQ[1]* signals are used as interrupt
output signals. Consequently, external interrupt requests can only be used when in the PCI External
Arbiter mode. Also, internal interrupt requests are assigned to interrupt number 13 of the Interrupt
Controller (IRC).
The following six registers set the interrupts.
•
Interrupt Request Flag Register (IRFLAG0, IRFLAG1)
•
Interrupt Request Polarity Control Register (IRPOL)
•
Interrupt Request Mask Register (IRMASKINT, IRMASKEXT)
•
Interrupt Request Control Register (IRRCNT)
The following formulas derive the interrupt generation conditions:
Internal interrupt request =
(|((IRFLAG[15:0] ^ IRPOL[15:0]) & IRMASKINT[15:0]))^ IRRCNT.INTPOL
External interrupt request =
(|((IRFLAG[15:0] ^ IRPOL[15:0] ) & IRMASKEXT[15:0]))^ IRRCNT.EXTPOL
In the above formulas, "^" indicates Exclusive OR operations and "|" indicates reduction operators
that perform an OR operation on all bits.
Also, the External Interrupt OD Control bit (IRRCNT.OD) of the Interrupt Request Control Register
can select whether the external interrupt supply signal is open drain output or totem pole output.
IRRCNT.INTPOL
IRFLAG[15]
IRPOL[15]
IRMASK[15]
IRRCNT.EXTPOL
Figure 15.3.1 External Interrupt Request Logic
15-8
Chapter 15 Interrupt Controller
Internal Interrupt
Request
(0: Request present)
External Interrupt Request