Cronologic xTDC4, Руководство пользователя

Страница: 19 / 32

int size
The number of bytes occupied by the structure.
int version
A version number that is increased when the definition of the structure is changed. The incre-
ment can be larger than one to match driver version numbers or similar. Set to 0 for all versions
up to first release.
int tdc mode
TDC mode. Can be grouped or continuous. Currently supported: grouped.
crono bool t start rising Rising or falling edge trigger.
double dc offset[XTDC4 CHANNEL COUNT + 1]
Set the switching voltage for the input channels S, A - D (see figure 3.1 ).
ˆ
dc offset[0] : Start
ˆ
dc offset[1 - 4] : A - D
Supported range is -1.32V to +1.18V. This should be close to 50% of the height of the input
pulse. Examples for various signaling standards are defined as follows
#define DC OFFSET P NIM +0.35
#define DC OFFSET P CMOS +1.18
#define DC OFFSET P LVCMOS 33 +1.18
#define DC OFFSET P LVCMOS 25 +1.18
#define DC OFFSET P LVCMOS 18 +0.90
#define DC OFFSET P TTL +1.18
#define DC OFFSET P LVTTL 33 +1.18
#define DC OFFSET P LVTTL 25 +1.18
#define DC OFFSET P SSTL 3 +1.18
#define DC OFFSET P SSTL 2 +1.18
#define DC OFFSET N NIM -0.35
#define DC OFFSET N CMOS -1.32
#define DC OFFSET N LVCMOS 33 -1.32
#define DC OFFSET N LVCMOS 25 -1.25
#define DC OFFSET N LVCMOS 18 -0.90
#define DC OFFSET N TTL -1.32
#define DC OFFSET N LVTTL 33 -1.32
#define DC OFFSET N LVTTL 25 -1.25
#define DC OFFSET N SSTL 3 -1.32
#define DC OFFSET N SSTL 2 -1.25
The inputs are AC coupled. Thus, the absolute voltage is not important for pulse inputs. It is
the relative pulse amplitude that causes the input circuits to switch.
dc offset must be set to the
relative switching voltage for the input standard in use. If the pulses are negative, a negative
switching threshold must be set and vice versa.
xtdc4 trigger trigger[XTDC4 TRIGGER COUNT]
Configuration of the external trigger sources.
xtdc4 tiger block tiger block[XTDC4 TIGER COUNT] Configuration of the timing generator.
xtdc4 channel channel[XTDC4 CHANNEL COUNT]
Configure polaritiy, type and threshold for the TDC channels.
cronologic GmbH & Co. KG 14 xTDC4 User Guide