mbed library sources modified for open wear
Dependents: openwear-lifelogger-example
Fork of mbed-src by
targets/cmsis/TARGET_NXP/TARGET_LPC11XX_11CXX/cmsis_nvic.c
- Committer:
- janekm
- Date:
- 2014-09-16
- Revision:
- 310:6188e0254baa
- Parent:
- 30:91c1d09ada54
File content as of revision 310:6188e0254baa:
/* mbed Microcontroller Library - cmsis_nvic for LPC11U24 * Copyright (c) 2011 ARM Limited. All rights reserved. * * CMSIS-style functionality to support dynamic vectors */ #include "cmsis_nvic.h" /* In the M0, there is no VTOR. In the LPC range such as the LPC11U, * whilst the vector table may only be something like 48 entries (192 bytes, 0xC0), * the SYSMEMREMAP register actually remaps the memory from 0x10000000-0x100001FF * to adress 0x0-0x1FF. In this case, RAM can be addressed at both 0x10000000 and 0x0 * * If we just copy the vectors to RAM and switch the SYSMEMMAP, any accesses to FLASH * above the vector table before 0x200 will actually go to RAM. So we need to provide * a solution where the compiler gets the right results based on the memory map * * Option 1 - We allocate and copy 0x200 of RAM rather than just the table * - const data and instructions before 0x200 will be copied to and fetched/exec from RAM * - RAM overhead: 0x200 - 0xC0 = 320 bytes, FLASH overhead: 0 * * Option 2 - We pad the flash to 0x200 to ensure the compiler doesn't allocate anything there * - No flash accesses will go to ram, as there will be nothing there * - RAM only needs to be allocated for the vectors, as all other ram addresses are normal * - RAM overhead: 0, FLASH overhead: 320 bytes * * Option 2 is the one to go for, as RAM is the most valuable resource */ #define NVIC_RAM_VECTOR_ADDRESS (0x10000000) // Vectors positioned at start of RAM void NVIC_SetVector(IRQn_Type IRQn, uint32_t vector) { int i; // Space for dynamic vectors, initialised to allocate in R/W static volatile uint32_t* vectors = (uint32_t*)NVIC_RAM_VECTOR_ADDRESS; // Copy and switch to dynamic vectors if first time called if((LPC_SYSCON->SYSMEMREMAP & 0x3) != 0x1) { uint32_t *old_vectors = (uint32_t *)0; // FLASH vectors are at 0x0 for(i = 0; i < NVIC_NUM_VECTORS; i++) { vectors[i] = old_vectors[i]; } LPC_SYSCON->SYSMEMREMAP = 0x1; // Remaps 0x0-0x1FF FLASH block to RAM block } // Set the vector vectors[IRQn + 16] = vector; } uint32_t NVIC_GetVector(IRQn_Type IRQn) { // We can always read vectors at 0x0, as the addresses are remapped uint32_t *vectors = (uint32_t*)0; // Return the vector return vectors[IRQn + 16]; }