Table 52: ac characteristics – BECKHOFF ET1200 User Manual
Page 62
Electrical Specifications and Timings
III-52
Slave Controller
– ET1200 Hardware Description
Table 52: AC Characteristics
Symbol
Parameter
Min
Typ
Max
Units
f
CLK25
Clock source (OSC_IN) with initial accuracy
25 MHz ± 25 ppm
t
CLK25OUT
CLK25OUT rising edge after OSC_IN rising
edge
22
ns
t
TX_delay
TX_ENA/TX_D[3:0] edge (TX-Shift = 00) after
rising edge of
a) OSC_IN
b) CLK25OUT
a) 4
b) 22
ns
t
CPU_CLK
CPU_CLK (25 MHz) rising edge after OSC_IN
rising edge
4
t
POR_Sample
POR value sample time after power good
84
ms
t
Driver_Enable
Output drivers enabled after POR values
sampled (not PDI and not Sync/LatchSignals)
80
ns
t
Reset_In
External reset input time
50
ns
t
Reset_Out
ET1200 Reset output time
80
84
ms
t
Reset_Func
ET1200 functional after RESET signal high
(EEPROM not loaded, PDI not functional)
50
µs
t
Startup
Startup time (PDI operational after power
good, without SII loading error)
340
ms
The AC characteristics of the PDIs, Distributed Clocks, SII EEPROM I
2
C interface, and MII interface
can be found in their respective chapters.