CM1K Hardware User’s Manual
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6.5.6
V_DATA
Video Data or Vector Data depending on the VI_EN settings:
If VI_EN=0, this 8-bit data signal can come from a sensor or be generated by an external controller.
If VI_EN=1, this 8-bit data signal must be connected to the 8 highest bit of the video signal.
6.6
Recognition stage output lines
6.6.1
B_BSY
The Bus Busy line is asserted during the execution of an internal cycle such as a reset cycle, a recognition cycle, an
I2C read or write command received from an external controller, etc. An external master controller must verify
that B_BSY is low prior to sending a command. Otherwise the command will be discarded. This signal is updated at
the negative edge of the G_CLK.
6.6.2
DIST_VAL
The Distance Valid signal rises on the negative edge of G_CLK when the real time distance (Addr 0x01D) of the last
recognition is available on the DATA output bus. This strobe lasts one clock cycle.
6.6.3
CAT_VAL
The Category Valid signal rises on the negative edge of G_CLK when the real-time category (Addr 0x1E) of the last
recognition is available on the DATA output bus. This strobe lasts one clock cycle.
6.7
U
I2C serial bus
The CM1K I2C slave controller can receive commands from an external I2C master controller operating at a speed
of 100 or 400 Kbit per second. It is enabled by setting the I2C_EN pin to 1. It converts the clock and serial data
received on the I2C_SCK and I2C_SDA pins into an internal data strobe signal (DS), Read/Write signal (RW_),
register value (REG) and data value (DATA). If the STANDALONE pin is set to 0, these signals are also be
broadcasted to the bidirectional parallel bus of the chip for use by the other CM1K chips.
6.7.1
I2C_EN
I2C_EN enables the CM1K to communicate with an external I2C master controller. If several CM1K chips are
connected in parallel, only one chip can have its I2C_EN pin set to 1. In addition, if the chain of CM1Ks shall
recognize a video or other digital signal received by one of them through its digital bus, the chip with its pin
RECO_EN=1 must be the same as the chip with its pin I2C_EN=1. This pin is connected to an internal pull-up so it is
enabled by default. For power-savings consideration, it should be grounded if unused.
6.7.2
I2C_CLK
Serial Clock. Must be connected to a pull-up resistor of 4.7 KOhms.
6.7.3
I2C_DATA
Serial Data. Must be connected to a pull-up resistor of 4.7 KOhms.