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Programmable Interrupt Controller Registers
12-20
élanSC520 Microcontroller Register Set Manual
Programming Notes
This register should be programmed only when the corresponding interrupt channel mask bits are set in the PIC.
For NMIs, this register should be programmed only when bit NMI_ENB is cleared in the PICICR register (see page 12-4).
NMI_ENB can be set immediately after programming this register (ECCMAP) to allow NMIs to be passed to the CPU.
Programming more than one interrupt source to an interrupt channel results in interrupt sharing on that channel.
Programming more than one interrupt source as an NMI source results in NMI sharing on the CPU’s NMI input.
All interrupt and NMI sources can be found in the following register descriptions:
I
Software Interrupt 16–1 Control, page 12-10
I
Software Interrupt 22–17/NMI Control, page 12-13
I
PCI Host Bridge Interrupt Mapping, page 12-17
I
ECC Interrupt Mapping, page 12-19
I
Other interrupt mapping registers (30), page 12-21
4
–
0
ECC_IRQ_MAP
[4–0]
SDRAM ECC Interrupt Mapping
The value in this 5-bit field maps the internally-generated SDRAM ECC single-bit interrupt to
one of the following interrupt priority channels on the microcontroller.
00000 = Disables the internally-generated ECC interrupt from reaching the PIC
00001 = Priority P1 (Master PIC IR0) (Highest priority)
00010 = Priority P2 (Master PIC IR1)
00011 = Priority P3 (Slave 1 PIC IR0/Master PIC IR2)
00100 = Priority P4 (Slave 1 PIC IR1)
00101 = Priority P5 (Slave 1 PIC IR2)
00110 = Priority P6 (Slave 1 PIC IR3)
00111 = Priority P7 (Slave 1 PIC IR4)
01000 = Priority P8 (Slave 1 PIC IR5)
01001 = Priority P9 (Slave 1 PIC IR6)
01010 = Priority P10 (Slave 1 PIC IR7)
01011 = Priority P11 (Master PIC IR3)
01100 = Priority P12 (Master PIC IR4)
01101 = Priority P13 (Slave 2 PIC IR0/Master PIC IR5)
01110 = Priority P14 (Slave 2 PIC IR1)
01111 = Priority P15 (Slave 2 PIC IR2)
10000 = Priority P16 (Slave 2 PIC IR3)
10001 = Priority P17 (Slave 2 PIC IR4)
10010 = Priority P18 (Slave 2 PIC IR5)
10011 = Priority P19 (Slave 2 PIC IR6)
10100 = Priority P20 (Slave 2 PIC IR7)
10101 = Priority P21 (Master PIC IR6)
10110 = Priority P22 (Master PIC IR7) (Lowest priority)
10111–11111 = Disables the internally-generated ECC interrupt from reaching the PIC
For example, if ECC_IRQ_MAP = 01101b, the ECC interrupt request is mapped to interrupt
priority P13 in the microcontroller. If ECC_IRQ_MAP = 00000b or any binary value from
10111–11111b, the ECC interrupt request is disabled from reaching the microcontroller’s PIC.
The single-bit ECC interrupt request cannot be routed as a source for generating an NMI.
If bit S2 in the MPICICW3 register is cleared (see page 12-34), the Slave 1 PIC is bypassed,
so programming the ECC_IRQ_MAP bit field to a value in the range 00100–01010b does not
pass the interrupt request to the CPU. However, if this bit field is programmed to 00011b with
the S2 bit cleared, the ECC interrupt request is routed to the Master PIC IR2 input.
If bit S5 in the MPICICW3 register is cleared (see page 12-33), the Slave 2 PIC is bypassed,
so programming the ECC_IRQ_MAP bit field to a value in the range 01110–10100b does not
pass the interrupt request to the CPU. However, if this field is programmed to 01101b with the
S5 bit cleared, the ECC interrupt request is routed to Master PIC IR5 input.
Bit
Name
Function