Motorola M68CPU32BUG Manuel d'utilisateur Page 195

  • Télécharger
  • Ajouter à mon manuel
  • Imprimer
  • Page
    / 196
  • Table des matières
  • MARQUE LIVRES
  • Noté. / 5. Basé sur avis des utilisateurs
Vue de la page 194
USER CUSTOMIZATION
M68CPU32BUG REV 1 C-21
Q: After I made the parameter change for an external clock (FEXTAL) and tied MODCK low
on header P2 by jumping pin 28 to 64, nothing happens when I power up the BCC, i.e., no
signon message appears. Why doesn’t it work?
A: The trace between pins 2 and 3 of jumper J1 on the BCC must be cut and the jumper placed
over pins 1-2 of J1 before the external clock signal can reach the MCU EXTAL pin.
Q: How can I change the number of data bytes in the the S-records produced by the dump (DU)
command?
A: Change the SRECMAX parameter to alter the data count. Larger counts produce more
efficient data S-records, but some loaders cannot accomodate them and they are harder to
view/edit as text files. Thus the default is set to 32 ($20) data bytes per record.
Q: How can I move the register module base to $007FFF00 when it is controlled by a write-once
MM bit in the Module Control Register (MCR)?
A: Change the MCR_AND parameter so the MM bit position (bit 6) is zero. The PWR_INI
routine initializes the MCR register by first reading the register, OR’ing in the MCR_OR
parameter value and then AND’ing the result with the MCR_AND parameter value before
storing the resulting value back into the MCR register.
Q: How can I enable the Software Watchdog or change the Bus Monitor Timing when they are
controlled by the write-once System Protection Control Register (SYPCR)?
A: Change the SYPCR_OR and SYPCR_AND parameters to achieve the desired value to be
placed into the SYPCR register. The PWR_INI routine initializes the SYPCR register by
first reading the register, OR’ing in the SYPCR_OR parameter value and then AND’ing the
result with the SYPCR_AND parameter value before storing the resulting value back into the
SYPCR register. As the Software Watchdog timeout period is set to smaller and smaller
values, some CPU32Bug commands may fail to complete their tasks before the watchdog can
be serviced, which causes a system reset. If the value is too small, the CPU32Bug signon
message will never appear, as the MCU will be in a state of chronic reset.
Vue de la page 194
1 2 ... 190 191 192 193 194 195 196

Commentaires sur ces manuels

Pas de commentaire