Figure 20: Xhif, Symbol And Signals - Siemens ERTEC 200P-2 Manual

The address windows in the page registers (offset, range and buffer mode) can be con-
figured by the ARM926 over the APB provided the XHIF is not yet active (enabled). The
external host uses the register chip select XHIF_XCS_R for configuring the page regis-
ters.
The external host can also configure the page registers over the APB interface of the
XHIF. In this case, however, the page for the APB address range should not be changed,
as further changes to the page registers over APB will otherwise not be possible.
Important: This type of page configuration has not been released in the XHIF spec., but
was successfully used in previous ASIC (ERTEC 200P).

Figure 20: XHIF, Symbol and Signals

Two functions have been implemented with the 'XHIF_XCS_R_A20' input pin in the light
of restrictions on the ballout and package design of the ERTEC 200P. They allow the
signal at this input to be used:
as chip select for page configuration over the external host OR
as address line A20 ( page address range increased to 2 MByte)
Just how this input pin is used in the XHIF modules is set in the SCRB register
'XHIF_Mode' with the 'XHIF_Mode' bit:
Copyright © Siemens AG 2016. All rights reserved 184 ERTEC 200P-2 Manual
Technical data subject to change Version 1.0