Siemens ERTEC200 - Manual (Page 77)

7.3 LBU Address Mapping
The following table illustrates an example of the ERTEC 200 Address Mapping from the Perspective of an External Host
Processor:
Seg(1:0) AD(19:0) SEGMENT
Distribution
SEGMENT
Size
Comment
00 0_0000h 1MB 1MB Page SDRAM (1 Mbyte)
00 Range: 0010 0000h
00 F_FFFFh Offset: 2000 0000h
01 0_0000h 64k 1MB Page KRAM (64 Kbytes)
01 Range: 0001 0000h
01 0_FFFFh Offset: 1010 0000h
01 1_0000h 64k
01 Mirrored
01 F_FFFFh
10 0_0000h 128k 1MB Page ext. SRAM (128 Kbytes)
10 Range: 0002 0000h
10 1_FFFFh Offset: 3000 0000h
10 2_0000h 128k
10 Mirrored
10 F_FFFFh
11 0_0000h 16k 1MB Page APB I/O
11 Range: 0000 4000h
11 0_3FFFh Offset: 4000 0000h
11 0_4000h 16k
11 Mirrored
11 F_FFFFh
Table 22: Address Mapping from the Perspective of an External Host Processor on the LBU
Port
In this example, a maximum of 1 MB is addressed. The addresses A[19:0] of the host processor are wired to the
LBU_ADR [19:0] for this purpose. In addition, the addresses A[21:20] are necessary for the segment selection. These
are connected to the LBU pins LBU_SEG[1:0].
Host
ETEC200
LBU
ADR(21:0)
ADR(19:0)
ADR(21:20)
LBU_ADR(19:0)
LBU_ADR(20)
LBU_SEG(1:0)
Figure 12: Interconnection of Addresses between Host and ERTEC 200 LBU
Copyright © Siemens AG 2007. All rights reserved. 77 ERTEC 200 Manual
Technical data subject to change Version 1.1.0