UM10413
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© NXP B.V. 2011. All rights reserved.
User manual
Rev. 1 — 16 December 2011
33 of 268
NXP Semiconductors
UM10413
MPT612 User manual
VICIntEnable = 0x0000 06C0 ; SPI0, I2C0, UART1 and UART0 are enabled interrupts
=>
; bit10, bit9, bit 7 and bit6=1
VICDefVectAddr = 0x... ; holds address at what routine for servicing
; non-vectored IRQs (that is, UART1 and I2C) starts
VICVectAddr0 = 0x... ; holds address where UART0 IRQ service routine starts
VICVectAddr1 = 0x... ; holds address where SPI0 IRQ service routine starts
VICVectCntl0 = 0x0000 0026 ; interrupt source with index 6 (UART0) is enabled as
; the one with priority 0 (the highest)
VICVectCntl1 = 0x0000 002A ; interrupt source with index 10 (SPI0) is enabled
; as the one with priority 1
After any IRQ requests (SPI0, I
2
C, UART0 or UART1) are made, the MPT612 redirects
code execution to the address specified at location 0x0000 0018. For vectored and
non-vectored IRQs the following instruction can be placed at 0x0000 0018:
LDR pc, [pc,#-0xFF0]
This instruction loads PC with the address that is present in register VICVectAddr.
In case UART0, request is made, VICVectAddr is identical to VICVectAddr0, while in case
SPI0 request is made, the value from VICVectAddr1 is found here. If either UART0 or
SPI0 have not generated an IRQ request but UART1 and/or I
2
C are the reason, the
content of VICVectAddr is identical to VICDefVectAddr.
10. System control block
10.1 Summary
of
system
control block functions
The system control block includes several system features and control registers for a
number of functions that are not related to specific peripheral devices. These include:
•
Crystal oscillator
•
External interrupt inputs
•
Miscellaneous system controls and status
•
Memory mapping control
•
PLL
•
Power control
•
Reset
•
APB divider
•
Wake-up timer
Each type of function has its own register(s) if any are required, and unwanted bits are
defined as reserved in order to allow future expansion. Unrelated functions never share
the same register addresses.
10.2 Pin
description
shows pins that are associated with system control block functions.