AW: C5402's clock mode

Started by Thomas Hupp August 10, 1999

-----Ursprungliche Nachricht-----
Von: Yi Li [SMTP:]
Gesendet am: Montag, 9. August 1999 18:46
An: c54x
Betreff: [c54x] C5402's clock mode

Hi! all,

A 10Mhz external crystal is used to enable the internal oscillator of
C5402, in order to let the DSP work at 100 Mhz, the hardware pins
CLKMD[3,2,1] are set to be "1,0,0" so that the PLL multiplier should be
10, and the reset value of register CLKMD (address 58h) should be 9007h.
However, the CLOCKOUT is not 100MHz but 120MHz, and the register CLKMD
is B007h! I don't think this register can be modified manually, it is
just determined by the clock
mode pins.
Even worse, while I debug another board with same hardware
pins configuration, the content of CLKMD register varies from 2007H to

Could anybody give me any hints on this problem? Thanks a lot!


[Thomas Hupp (TH)]
The CLKMD - Pins only determine the clock rate at startup of prozessor -
after startup the register CLKMD can be modified manualy (Look for
documentation TMS320C54X Reference Set 1, Page 8.18...).