Content originally posted in LPCWare by Dave on Tue Aug 23 09:14:45 MST 2011 So, while we're on the subject of Keil's tool, and the schematic of the clocks, I noticed that when I run my USBLite (modified) program, (which works, by the way), and I have a look at the schematic in the debugger, the clock values look like this:
Content originally posted in LPCWare by usb10185 on Tue Aug 23 06:57:24 MST 2011 Hi Marc, Where in Keil is this Clock Generation Schematic tool? I can not see it in my setup. Just the configuration wizard.
Content originally posted in LPCWare by nxp21346 on Tue Aug 16 15:16:00 MST 2011 It looks like there is an error in the part User's Manual and the CMSIS Clock setup code. There is a design restriction that the EMC cannot run faster than the CPU clock. To implement this, functionally, the EMC Clock Divider is fed from the CPU clock divider and not from the CPU clock select mux as shown in the User's Manual diagram and the posted diagram from the Keil tool. The behavior of the Keil tool in calculating EMC Clock as CPU Clock / 2 is correct.
Note: The EMC also cannot exceed 80 MHz. This is the reason for the /2 divide option from CPU clock (which can reach 120 MHz)