Design-In - Electrical Aspects
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COMX Communication Modules | Design Guide
DOC100901DG18EN | Revision 18 | English | 2013-12 | Released | Public
© Hilscher, 2002-2013
The following table explains the available possibilities:
Modules
Host address space
Connect to
Address lines to be con-
nected with 560
Ω
pull-
down
COMX 10
8 KByte
A0..A12
A13
COMX 10/50/51/100
16 KByte
A0..A13
none
Table 19: Possibilities for Usage of Dual-Port Memory
3.1.2
Host Interface: Parallel or serial Dual-Port Memory Mode
3.1.2.1
COMX 50 and COMX 100
COMX 50 and COMX 100 Modules support one host interface mode: parallel dual-port memory
mode.
How to set the 8 or 16 bit data with in parallel dual-port memory mode
The data width of the dual-port memory can be set to 8 or 16 bit. The data width is set at
DPM_SIRQn during the start-up phase.
A high signal at DPM_SIRQn sets the data width of 8 bit: pin is unconnected.
A low signal at DPM_SIRQn sets the data width of 16 bit: 680
Ω
pull-down resistor.
3.1.2.2
COMX 10 and COMX 51
COMX 10 and COMX 51 Modules support two host interface modes:
parallel dual-port memory mode and the
serial dual-port memory mode.
This can be configured by the level of the mode setting signal, which is evaluated during start-up
phase of the module.
How to set the host interface mode
Parallel Dual-Port Memory Mode
A high signal at DPM_DIRQn during start-up phase activates the dual-port memory mode.
The data width of the dual-port memory can be set to 8 or 16 bit. The data width is set at
DPM_SIRQn during the start-up phase.
A high signal at DPM_SIRQn sets the data width of 8 bit: pin is unconnected.
A low signal at DPM_SIRQn sets the data width of 16 bit: 680
Ω
pull-down resistor.
Serial Dual-Port Memory Mode
A low signal at DPM_DIRQn activates the serial dual-port memory mode (via a 680
Ω
pull-
down resistor). Pin DPM_SIRQn: let the input open.
Signals DPM_DIRQn and DPM_SIRQn have a pull-up resistor of 4,7 k
Ω
on the COMX 10 or 51
Module.
Important:
Never drive the host interface mode signal (DPM_DIRQn). Instead, operation with pull-
down and pull-up resistors is recommended.