MT9V032
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60
APPENDIX B − POWER−ON RESET AND STANDBY TIMING
Reset, Clocks, and Standby
There are no constraints concerning the order in which the
various power supplies are applied; however, the MT9V032
requires reset in order operate properly at power−up. Refer
to Figure 49 for the power−up, reset, and standby sequences.
Figure 49. Power−up, Reset, Clock and Standby Sequence
non−Low−Power
Low−Power
non−Low−Power
Power
down
Wake
up
ActiveStandby
Pre−StandbyActive
Power
up
MIN 20 SYSCLK cycles
Note 3
RESET #
STANDBY
SYSCLK
MIN 10 SYSCLK cycles
Does not
respond to
serial
interface
when
STANDBY = 1
MIN 10 SYSCLK cycles
MIN 10 SYSCLK cycles
D
OUT
[9:0]
D
OUT
[9:0]
DATA OUTPUT
SCLK, S
DATA
Two−Wire
Serial
I/F
Driven
=
0
V
DD,
V
DD
LVDS
V
AA,
VAAPIX
1. All output signals are defined during initial power−up with RESET# held LOW without SYSCLK being active. To properly
reset the rest of the sensor, during initial power−up, assert RESET# (set to LOW state) for at least 750ns after all power
supplies have stabilized and SYSCLK is active (being clocked). Driving RESET# to LOW state does not put the part in
a low power state.
2. Before using two−wire serial interface,wait for 10 SYSCLK rising edges after RESET# is de−asserted.
3. Once the sensor detects that STANDBY has been asserted, it completes the current frame readout before entering
standby mode. The user must supply enough SYSCLKs to allow a complete frame raedout. See Table 4, “Frame Time,”
for more information.
4. In standby, all video data and synchronization output signals are High−Z.
5. In standby, the two−wire serial interface is not active.
Standby Assertion Restrictions
STANDBY cannot be asserted at any time. If STANDBY
is asserted during a specific window within the vertical
blanking period, the MT9V032 may enter a permanent
standby state. This window (that is, dead zone) occurs prior
to the beginning of the new frame readout. The permanent
standby state is identified by the absence of the
FRAME_VALID signal on frame readouts. Issuing a
hardware reset (RESET# set to LOW state) will return the
image sensor to default startup conditions.
This dead zone can be avoided by:
1. Asserting STANDBY during the valid frame
readout time (FRAME_VALID is HIGH) and
maintaining STANDBY assertion for a minimum
of one frame period.
2. Asserting STANDBY at the end of valid frame
readout (falling edge of FRAME_VALID) and
maintaining STANDBY assertion for a minimum
of [5 + R0x06] row−times.
When STANDBY is asserted during the vertical blanking
period (FRAME_VALID is LOW), the STANDBY signal
must not change state between [Vertical Blanking Register
(R0x06) − 5] row−times and [Vertical Blanking Register
+ 5] row−times after the falling edge of FRAME_VALID.
