- SS-HQ1 Application Notes -
Ver.1.0.0 January 7, 2005
62
9.1.5. Serial Communication Prohibited Period
A serial communication prohibited period is set during the time period preceding and following the VD fall.
Communication from the exterior is not accepted during the periods shown in the diagram below.
Fig 9.1-4 Serial Communication Prohibited Period
9.1.6. Important Note Regarding Communication
The serial communication clock is made by frequency-dividing the CXD3172AR’s encoder clock (ECK).
Therefore, communication may not work properly in cases where MODESEL is not set correctly, or when the
ECK frequency shifts significantly from the recommended value.
9.1.7. When Communication is Not Used
In order to prevent operation errors in cases where the serial interface is not being used, set the pins as shown
in
Table 9.1-5 Pin Settings When Communication is Not Used
Pin name
Pin No
State
XCS 15 H
SCK 18 H
SIFSEL 13
L
SI
16
H or L
SO 17 Open
VD
Communication prohibited period
0.3ms
2H
0.3ms
2H
Communication prohibited period