Ahb Arbiters; Ahb Multi-Layer Configuration; Table 6: Fixed Priority Assignment (No Default) - Siemens ERTEC 200P-2 Manual

The AHB slave modules allow the following types of access:
AHB module (slave)
PN-IP *)
Peripheral interface
EMC memory
EMC register
GDMA (RAM + Regis-
ter)
ARM-ICU
ARM926 - TCM
ARM926 - ETB
*) Handling of access over AHB within the modules varies. Please see the module specifications/section on the relevant module.

AHB Arbiters

2.3.2.3.1
Each of the AHB arbiters uses the same arbitration procedure. The default setting is
round robin. A fixed priority assignment for the AHB masters (see Table 6: Fixed priority
assignment (no default)) could be used as an alternative arbitration algorithm by program-
ming the ARB_MODE bit in the SCRB register M_LOCK_CTRL (see 2.3.10.9.22). This
option should not, however, be implemented in the light of the dynamic processes at the
multi-layer AHB.
Using round robin as the arbitration procedure prevents the AHB masters from blocking
each other at the multi-layer AHB for a prolonged period of time (cf. 2.3.2.3.2)

AHB Multi-layer Configuration

2.3.2.3.2
The masters in the multi-layer AHB are not connected to all slaves. The table below
shows which AHB master is connected to which AHB slave.
5
No fixed priority is assigned to the PN-IP-M2 master as the connection to the PER-PN-S10 is point-to-point. This
prevents a conflict from ever occurring at PER-PN-S10.
Copyright © Siemens AG 2016. All rights reserved
Technical data subject to change
Access permit-
ted
8/16/32-bit
8/16/32-bit
8/16/32-bit
8/16/32-bit
Only 32-bit
Only 32-bit
8/16/32-bit
8/16/32-bit
PRIORITIES MASTER
Host inter-
7
6 GDMA
5 PN-IP-M1
4
3
2 ARM926-D
1 ARM926-I

Table 6: Fixed priority assignment (no default)

S1 S2 S3 S5
Comment
Data bus: 32-bit
Data bus: 32-bit
Data bus: 32-bit
Data bus: 32-bit
Data bus: 32-bit
Data bus: 32-bit
Data bus: 32-bit
Data bus: 32-bit
NOTES
Highest priority
face
5
----
-----
Lowest priority
S6 S7
45
S9 S10 S12
ERTEC 200P-2 Manual
Version 1.0