The Control Tables (CTABs)
The Neon
NEO-2-14
BitFlow, Inc.
Version G.5
VSTART defines the start of the Vertical Acquisition Window (VAW), if the start is pro-
vided by the VCTAB, see previous section.
VRESET defines the reset of the VCOUNT, in case this function is programmed in the
VCTAB.
ENVLOAD enables the FEN to load the VCOUNT. The rationale behind the ENVLOAD
column from the VCTAB is that some cameras might not give a FEN, but only two
pulses: the start and end of FEN. With the ENVLOAD, we can mask out the unwanted
one.
IRQ provides an interrupt to the host, allowing an interrupt to occur at any point on
the vertical axis.
GPV are general purpose vertical functions, see usage below.
Note: If a VRESET pulse happens coincident with a LOAD, the LOAD is overriding.
The CLOCK_V Control
CLOCK_V is the clocking of the VCOUNT is generated by the end of the line (horizon-
tal reset).
The INC_V Control
INC_V is the logic for incrementing VCOUNT.
There are only two instances when we want to inhibit the incrementing of VCTAB. The
first instance is when VCOUNT reaches 0000h, the “Stop at Zero” case. The other
instance is when VCOUNT reaches 7FF0h, the “Vertical Stick” case.
Stop at Zero
Usually, VCOUNT will reach zero because of a RESET_V signal. After VCOUNT is reset,
there are programmable options defined by VCNT_RLS_ZERO. Depending on this
bitfield, VCOUNT can continue to count or wait at zero till some event occurs, usually
the assertion of the TRIGGER.
This operating mode is especially useful for synchronizing cameras to external events.
TRIGGER is usually the output of a part-in-place signal. Until this signal is asserted, the
VCOUNT waits at address 0000h. After the TRIGGER is asserted, VCOUNT starts
counting, i.e., scanning the VCTAB in ascending order. At some address we will pro-
gram a sync signal to be sent to the camera, usually through GPV0. In response to this
sync signal, the camera will give back a frame, and it will assert FEN. The FEN will load
address 8000h into VCOUNT. In the VCTAB, we will program the vertical acquisition
window to start after address 8000h. At the end of the vertical acquisition window the
RESET_V will be asserted, which in turn will reset the VCOUNT. VCOUNT will wait at
address 0000h until TRIGGER is asserted.
Summary of Contents for NEO-PCE-CLB
Page 8: ... TOC 6 BitFlow Inc Version ...
Page 22: ...Virtual vs Hardware Frame Grabbers The Neon NEO 1 12 BitFlow Inc Version G 5 ...
Page 64: ...NTG Control Registers The Neon NEO 3 6 BitFlow Inc Version G 5 ...
Page 90: ...PoCL Control Registers The Neon NEO 6 6 BitFlow Inc Version G 5 ...
Page 266: ...Power Consumption The Neon NEO 12 6 BitFlow Inc Version G 5 ...
Page 294: ...NEO PCE DIF I O Connector Pinout P3 The Neon NEO 13 28 BitFlow Inc Version G 5 ...
Page 300: ...Index BitFlow Inc ...