Siemens SPC3 Timing Characteristics, SYS Bus Interface, Clock pulse 48 Mhz, Clock Pulse Timing

PROFIBUS Interface Center SPC3

8.5 Timing Characteristics

The following is generally applicable: All signals beginning with ‘X’ are ‘low active’. All signal runtimes are based on the capacitive loads specified in the table above.

8.5.1 SYS Bus Interface

Clock Pulse:

No.	Parameter	MIN	MAX	Unit
	Clock pulse 48 Mhz :
1	Clock High Time	6.25	14.6	ns
2	Clock Low Time	6.25	14.6	ns
3	Rise Time		4	ns
4	Fall Time		4	ns

Clock Pulse Timing:

	TCLH
	1
CLK	2,4V
	0,6V
	3

TCLL

2

4

Distortions in the clock pulse signal are permitted up to a ratio of 40:60. At a threshold of 1.5 or 3.5 V:

Interrupts:

No.	Parameter	MIN	MAX	Unit
1	Interrupt Inactive Time (for EOI_Timebase = 0)	1	1	μs
	Interrupt Inactive Time	1	1	ms

X/INT

EOI

1

After acknowledging an interrupt with EO1, a min. of 1 us or 1 ms is expected in SPC3 before a new interrupt is output.

Page 46	V1.3	SPC3 Hardware Description
2003/04		Copyright (C) Siemens AG 2003. All rights reserved.