9 SRAM CONTROLLER (SRAMC)
9-2
Seiko Epson Corporation
S1C33L26 TECHNICAL MANUAL
SRAMC Operating Clock
9.3
The SRAMC operates with BCLK supplied from the CMU. BCLK does not stop in normal mode and in HALT
mode by default. It can be stopped in HALT mode using a CMU control register. BCLK can also be output to exter-
nal devices from the CMU_CLK pin. For more information on BCLK, see the “Clock Management Unit (CMU)”
chapter. In SLEEP mode, the CMU stops supplying BCLK to the SRAMC.
PCLK2 and SDCLK are also used for accessing the SRAMC control registers and the area for SDRAM, respec-
tively.
External Memory Areas
9.4
The SRAMC supports an external memory space, which is divided into 14 areas as shown in Figure 9.4.1.
Area 13
0x02ff ffff
0x0200 0000
Area 12
0x01ff ffff
0x0180 0000
Area 11
0x017f ffff
0x0100 0000
Area 10
0x00ff ffff
0x00c0 0000
Area 9
0x00bf ffff
0x0080 0000
Area 8
0x007f ffff
0x0060 0000
Area 7
(
*
1)
0x005f ffff
0x0040 0000
Area 6
0x003f ffff
0x0030 0000
(Reserved area for internal
peripheral modules)
Area 5
0x002f ffff
0x0020 0000
Area 4
0x001f ffff
0x0010 0000
Area 15
0x05ff ffff
0x0400 0000
Area 14
0x03ff ffff
0x0300 0000
External memory
16M bytes
Reserved
Reserved
External memory
4M bytes
External memory
4M bytes
External memory
2M bytes
External memory
2M bytes
External memory
1M bytes
External memory
1M bytes
Area 18
0x0fff ffff
0x0c00 0000
Area 17
0x0bff ffff
0x0800 0000
Area 16
0x07ff ffff
0x0600 0000
Reserved
Area 19
(
*
1)
0x1fff ffff
0x1000 0000
External memory
256M (64M) bytes (
*
2)
Area 20
0x3fff ffff
0x2000 0000
External memory
512M (64M) bytes (
*
2)
Area 21
0x7fff ffff
0x4000 0000
External memory
1G (64M) bytes (
*
2)
Area 22
0xffff ffff
0x8000 0000
External memory
2G (64M) bytes (
*
2)
Reserved
External memory
32M bytes
External memory
32M bytes
External memory
16M bytes
#CE4
●
●
#CE5
●
●
●
#CE7
●
●
#CE8
●
●
#CE9
●
●
#CE10
●
●
●
*
1
Usable as an SDRAM area.
*
2
Since the address bus is 26-bit wide, valid area for each area is 64M bytes from the top.
4.1 S1C33L26 External Memory Space
Figure 9.
Areas 4, 5, 7 to 10, 13 to 16, and 19 to 22 comprise an external memory area accessible from the SRAMC, to which
external memory devices may be connected. The access conditions can be set by area, including the device type and
size as well as the number of wait cycles.