Siemens 620 appendix SBHE# MEMCS16#, DACK0# MEMR# DRQ, Memw#, DACK5#, DACK6#, DACK7#

Hardware Information

Pin	Designation	Type *	Pin	Designation	Type
C1	–SBHE#	O	D1	–MEMCS16#	I
C2	LA 23	I/O	D2	–IOCS16#	I
C3	LA 22	I/O	D3	IRQ 10	I
C4	LA 21	I/O	D4	IRQ 11	I
C5	LA 20	I/O	D5	reserved	I
C6	LA 19	I/O	D6	reserved	I
C7	LA 18	I/O	D7	reserved	I
C8	LA 17	I/O	D8	–DACK0#	O
C9	–MEMR#	I/O	D9	DRQ 0	I
C10	–MEMW#	I/O	D10	–DACK5#	O
C11	SD 08	I/O	D11	DRQ 5	I
C12	SD 09	I/O	D12	–DACK6#	O
C13	SD 10	I/O	D13	DRQ 6	I
C14	SD 11	I/O	D14	–DACK7#	O
C15	SD 12	I/O	D15	DRQ 7	I
C16	SD 13	I/O	D16	+ 5V	VCC
C17	SD 14	I/O	D17	reserved	I
C18	SD 15	I/O	D18	0 V	GND

#low active

Under normal conditions, the signals -SBHE, LA17 - LA23, -MEMR and MEMW are operated as outputs (sending from the CPU). Only CPU boards which are suitable for use as a master CPU for system bus access send and receive these signals. A minus sign “-” in front of the signal name shows that the signal is LOW active.

SIMATIC Box PC 620 Manual	7-33
A5E00131465-01