TDC-GP2 acam messelectronic gmbh, TDC-GP2 Datasheet - Page 25

• Manufacturer Part Number: TDC-GP2
• Description: Precision Time Interval Measurement
• Manufacturer: acam messelectronic gmbh

Now all hit data are available from registers 0 to 2.
The load pointer value is 3.
At the end the TDC-GP2 has to be initialized again to be
ready for the next measurement. This is done by
sending the opcode "Init" so that the TDC accepts new
Start and Stop hits.
4.2 Stop Masking
The TDC-GP2 can set time-based masking windows for
each of the 3 hits on Stop1 input when no hits are
accepted. The masking refers to the start event and
has an accuracy of less than 10 ns.
The internal enable unit is connected to the external
enable pin by a logical AND. The external enable pin
must be set to “1” to use the internal masking unit.
The configuration settings are made in registers 2 to
4, DELVAL1, DELVAL2 and DELVAL3:
It is mandatory that if not all registers are used the
mask values that are not required are set to “0”. When
all DELVAL registers are set to 0, the complete unit is
disabled.
Example:
4 Mhz reference, ClkHSDiv = 1
DELVAL1 = 0x3200
DELVAL2 = 0x3300
DELVAL1 = 0x3400
DELVAL1 … DELVAL3 are fixed point numbers with
14 bit integer and 5 bit fractional digits, in
multiples of the internal reference clock
The minimum mask size is 3 clock cycles
The mask values must have an ascending order.
Each mask value must be 3 clock cycles bigger than
the previous value
Delay
( 400*Tref)
( 408*Tref)
( 410*Tref)
min
acam-messelectronic gmbh - Am Hasenbiel 27 - D-76297 Stutensee-Blankenloch - Germany - www.acam.de
DELVALX
T
ref
1
200 µs after Start
2
204 µs after Start
3
208 µs after Start
s t
n d
r d
Stop not accepted before
Stop not accepted before
Stop not accepted before
ClkHSDiv
25
TDC-GP2
4.2 Stop Masking