![Samsung S3C2501X User Manual Download Page 195](http://html.mh-extra.com/html/samsung/s3c2501x/s3c2501x_user-manual_340828195.webp)
SYSTEM CONFIGURATION
S3C2501X
4-4
Data bus width configuration
(8/16/32-bit)
External address pins
ADDR[23:0]
8 bit
16 bit
32 bit
External
Internal
HADDR[23:0]
HADDR[24:1]
HADDR[25:2]
Figure 4-2. External Address Bus Diagram
4.6 ARBITRATION SCHEME
The S3C2501X can support the fixed priority and the round-robin method for AHB bus arbitration by register
setting. Especially, the S3C2501X can program the priority order in the fixed priority mode as well as the ratio of
the bus occupancy in the round-robin priority mode.
The internal function blocks or AHB bus masters are divided into three groups, Group A, Group B, and Group C.
Group A has only Test Interface Controller (TIC) block. The Group A has the highest bus priority. Group B has 3
AHB bus masters, General DMA, Ethernet Controller 0, Ethernet Controller 1. The S3C2501X can program the
bus priority of each bus masters among Group B. So the bus priority of bus masters in only Group B can be
programmed. Group C has the ARM940T CPU. The relative priority of Group B and Group C is determined more
or less in an alternating manner.
The local priority of six channels of general DMA can be programmed by fixed priority or round-robin priority in
similar manner to the AHB bus priority. Please refer to the general DMA chapter.
Table 4-2. AHB Bus Priorities for Arbitration
Function Block
AHB Bus Priority (Group)
Test Interface Controller (TIC)
Group A (highest priority)
General DMA (GDMA)
Group B
Ethernet Controller 0
Group B
Ethernet Controller 1
Group B
ARM940T CPU
Group C
Summary of Contents for S3C2501X
Page 18: ......
Page 275: ...MEMORY CONTROLLER S3C2501X 5 60 NOTES ...
Page 289: ...I2C CONTROLLER S3C2501X 6 14 NOTES ...
Page 373: ...GDMA CONTROLLER S3C2501X 9 24 NOTES ...
Page 435: ...I O PORTS S3C2501X 12 12 NOTES ...