At Reset Or Power Up - NEC mPD7755 User Manual

3.4.4 At reset or power up
cs
If the RESET signal is input while a speech is being
synthesized, or on power application, the data input to
the O/A converter is undefined but within the limit of 0
to 100H.
If speech synthesis is started under this condition with
both the ST and CS pins being low level, the input data
of the O/A converter is shifted to 100H and then the
speech is output.
The input to the O/A converter is shifted gradually to
100H in the same manner as described in section 3.3, the
synthesized speech will be output a maximum of 47ms after
the RESET signal has been input or the power has been
applied .
H - - \
I
L -
L--.I
H _ _ _ --,
V S T pulse
I I
L -
I--f
tcc
width
I' - I' : ___
~Q
I - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
I
H ______
~I
_ _ _
~
BUSY \ ; -
L
I~-------------------'
I
Speech output start time
BUSY output time
t
SBO
I ,
I
tsso ,
I :
_ _ _ _ _ _ _ _ _ _ _ _
~Kr----s-p-e-e-c-h-o-u-t-p-u-t----~)~-
_ _
I~-----------~
AVO
Fig. 3- 8 Speech Synthesis Start Input
(When ST Input is pulse)
3-10