DSP Interrupt Interface
8-30
8.5.4.1
Level-Sensitive Clear Commands (Write Only)
A write transaction issues a clear to those interrupt channels whose assigned
bit in the 16-bit word being written is 1. Commands to clear interrupt channels
are necessary for those channels assigned as level-sensitive interrupt chan-
nels. Figure 8–6 illustrates the alignment of the channel clear assignments
within the 16-bit word written to the XIO interrupt processor and gives the
permissible range of addresses over which the write can take place.
A write to the level-sensitive clear low register (RST_LVL_LO), whose offset
address is 02, clears interrupts corresponding to nXIRQ[15:0].
Table 8–33. Level-Sensitive Clear Low Register (RST_LVL_LO)
Bit
Name
Value
Description
Type
Reset
Value
15–0
Reset_CHx
Reset CHx if a 1 is written into RST_LVL_LO[x] and CHx
is configured as level-sensitive interrupt, where CHx
corresponds to interrupt channels nXIRQ[15:0]
0
0
0
Do not reset CHx.
1
Reset interrupt channel CHx if level is configured as level
sensitive.
A write to the level-sensitive clear high register (RST_LVL_HI), whose offset
address is 03, clears interrupts from interrupt channels [20:16], NMI, and
HOSTINT.
Table 8–34. Level-Sensitive Clear High Register (RST_LVL_HI)
Bit
Name
Value
Description
Type
Reset
Value
7
Reset_NHOSTINT
Reset NHOSTINT channel if a 1 is written into this
bit and NHOSTINT is configured as level-sensitive
interrupt.
0
Do not reset NHOSTINT.
1
Reset NHOSTINT interrupt channel, if configured
as level-sensitive interrupt.
6
Reset_NMI
Reset NMI channel if a 1 is written into this bit and
NMI is configured as level-sensitive interrupt.
0
Do not reset CHx.
1
Reset NMI interrupt channel if configured as
level-sensitive interrupt.