about the system clock config
Dear Wolfgang Denk:
I have configed my WindRiver mdppro8xx board
according to the TQM8xxL module.The outcome is :
________________
U-Boot 0.4.8 (Oct 31 2003 - 15:47:15)
gd->cpu_clk=25000000
immr=0xff002101
pvr=0x500000
CPU: XPC823xxZTnnB2 at 25 MHz: 2 kB I-Cache 1 kB
D-Cache
Board: WindRiver mdppro8xx DRAM: 16 MB
before relocate_code()
----------------
Now I want to set my system clock to 50MHz.
In the TQM8XXL.h there are clauses like these:
__________________
"#if defined(CONFIG_80MHz)
.....
#elif defined(CONFIG_66MHz)
........
#else /* 50 MHz */
........."
------------------
so I added these:#define CONFIG_80/66/50MHz,but the
outcome are still :
________________
CPU: XPC823xxZTnnB2 at 25 MHz: 2 kB I-Cache 1 kB
D-Cache
----------------
Why did my #define CONFIG_80/66/50MHz not work? The gd->cpu_clk is evaluated in cpu/mpc8xx/speed.c by
gd->cpu_clk = measure_gclk();but the function
measure_gclk() seems have nothing to do with my
board.h,right? So where to modify my system clock to
50MHz?:-)
I have a vxWorks BSP of my WindRiver MDP8xx pro
board.Everything is OK in vxWorks enviroment,now I
want to run linux on it so the first thing is to port
u-boot to it.I have modified the system_clock
registers like SCCR/PLPRCR according to the romINIT.s
in vxworks bsp,but there are nothing outcome in the
hyperteminal.
Hello,
Quoted 3 lines · in message <[email protected]> you wrote:
I have configed my WindRiver mdppro8xx board
according to the TQM8xxL module.The outcome is :
This makes little sense unless you know EXACTLY what you're doing - and in this case you usually will start with a new config file from scratch.
Quoted 1 line
Now I want to set my system clock to 50MHz.
Do you know exactly how the clock systems are implemented on the TQM8xxL hardware, and on your board?
What makes you think that the TQM8xxL is so similar to your hardware that you can just copy the configuration and expect it would work?
Quoted 4 lines
so I added these:#define CONFIG_80/66/50MHz,but the
outcome are still :
________________
CPU: XPC823xxZTnnB2 at 25 MHz: 2 kB I-Cache 1 kB
This is obviously because you are on differetn hardware, which uses not the same input clocks as the TQM8xxL.
Quoted 1 line
Why did my #define CONFIG_80/66/50MHz not work?
Because your hardware is different.
Quoted 2 lines
board.h,right? So where to modify my system clock to 50MHz?:-)
Start reading the schematics of your board. The read the MPC860 User's Manual. Pay special attention to Chapter 15 Clocks and Power Control. Go through Figure 15-1 step by step and wrtie down all initialization values (MF bits, PLPRCR, SCCR, ...) needed for your hardware configuration. Then check where those values are set in the config file. Enter the correct values. Then try again.
I am afraid I cannot save you the effort of performing all these boring steps, but without in-depth understanding of what you're doing you will not succeed.
Best regards,
Wolfgang Denk
Signature · 4 lines
Software Engineering: Embedded and Realtime Systems, Embedded Linux Phone: (+49)-8142-4596-87 Fax: (+49)-8142-4596-88 Email: wd at denx.de Without freedom of choice there is no creativity. -- Kirk, "The return of the Archons", stardate 3157.4