GMS30C7201 Datasheet, PDF (76/352 Pages) Hynix Semiconductor – 60MHz operation frequency Low power consumption

SDRAM Controller
8.3 Supported Memory Devices
From 2–64Mbytes of SDRAM are supported with any mixture of up to four of 16-, 64- or
128Mbit devices. Each of the four external devices are mapped to a 16Mbyte boundary, and rely
on the memory management unit to map different mixtures of devices (for example, 16- and
64Mbit devices) into a continuous address space for the ARM. Note that 16Mbit devices appear
eight times, and the 64Mbit devices appear twice in the memory map.
Note
Total Memory
2Mbyte
4Mbyte
8Mbyte
16Mbyte
32Mbyte
64Mbyte
16Mbit devices
1
2
4
-
-
-
64Mbit devices
128Mbit devices
-
-
-
-
1
-
2
1
4
2
-
4
Table 8-3: SDRAM upgrade path
The GMS30C7201 can use any mixture of 16-, 64- or 128Mbit SDRAMs. It is the responsibility
of software to determine the actual external memory configuration, and to program the memory
management unit appropriately.
The SDRAM controller allows up to four banks of memory to be open at once. The open banks
may exist in different physical SDRAM devices.
8-4
GMS30C7201 Data Sheet