Content originally posted in LPCWare by Jonno on Wed Feb 24 05:42:29 MST 2016
Hi All,
I have a prototype circuit using an LPC1768 which communinicates with other devices using SPI. This works fine when using an external 12MHz oscillator to drive the LPC1768.
However, I typically use the internal oscillator for production boards, to save on cost. When I change to use the internal oscillator the code hangs when it does an SPI write.
The code I change for system_LPC17xx.c to use the internal oscillator is (in part):
// Use internal clock instead of external oscillator
#define CLOCK_SETUP 1
//#define SCS_Val 0x00000020
#define SCS_Val 0x00000000
// original value
//#define CLKSRCSEL_Val 0x00000001
#define CLKSRCSEL_Val 0x00000000
#define PLL0_SETUP 1
//#define PLL0CFG_Val 0x00050063
#define PLL0CFG_Val 0x00050066
#define PLL1_SETUP 0
#define PLL1CFG_Val 0x00000023
#define CCLKCFG_Val 0x00000003
#define USBCLKCFG_Val 0x00000000
#define PCLKSEL0_Val 0x00000000
#define PCLKSEL1_Val 0x00000000
#define PCONP_Val 0x042887DE
#define CLKOUTCFG_Val 0x00000000
Any suggestions on how I can get the SPI working again?
