9 SRAM CONTROLLER (SRAMC)
9-10
Seiko Epson Corporation
S1C33L26 TECHNICAL MANUAL
Note: Figures 9.6.2.1 and 9.6.2.2 assume a very low operating speed for convenience of explanation.
When actually using an external wait request, to allow for a delay due to noise filter of the #WAIT
pin, be sure to set the #CE setup cycles (CE
x
SETUP[1:0]) or static wait cycles (CE
x
WAIT[3:0]) as
follows:
• When using #WAIT, set CE
x
SETUP[1:0] to 0x1 or higher, or set CE
x
WAIT[3:0] to 0x1 or higher.
• When a #CE
x
signal is used to generate a #WAIT signal, set the conditions no lower than the
following.
CE
x
SETUP[1:0] = 0x1 and CE
x
WAIT[3:0] = 0x2, or
CE
x
SETUP[1:0] = 0x2 and CE
x
WAIT[3:0] = 0x1, or
CE
x
SETUP[1:0] = 0x3 and CE
x
WAIT[3:0] = 0x0
• When a #RD/#WRH/#WRL signal is used to generate a #WAIT signal, set the condition no
lower than the following.
CE
x
WAIT[3:0] = 0x3
When settings are other than the listed above, external wait is ineffective.
Control Register Details
9.7
7.1 List of SRAMC Registers
Table 9.
Address
Register name
Function
0x302220 SRAMC_TMG47
#CE[7:4] Access Timing Configuration Register Set #CE[7:4] access conditions
0x302224 SRAMC_TMG810
#CE[10:8] Access Timing Configuration Register Set #CE[10:8] access conditions
0x302228 SRAMC_TYPE
#CE[10:4] Device Configuration Register
Set #CE[10:4] device types
The following describes each SRAMC register. These are all 32-bit registers.
Note: When data is written to the registers, the “Reserved” bits must always be written as 0 and not 1.
#CE[7:4] Access Timing Configuration Register (SRAMC_TMG47)
Register name Address
Bit
Name
Function
Setting
Init. R/W
Remarks
#CE[7:4]
Access Timing
Configuration
Register
(SRAMC_
TMG47)
0x302220
(32 bits)
D31–30 CE7SETUP
[1:0]
#CE7 setup cycle
CE7SETUP[1:0] Setup cycle
0x3 R/W
0x3
0x2
0x1
0x0
4 cycles
3 cycles
2 cycles
1 cycle
D29–28 CE7HOLD
[1:0]
#CE7 hold cycle
CE7HOLD[1:0]
Hold cycle
0x3 R/W
0x3
0x2
0x1
0x0
4 cycles
3 cycles
2 cycles
1 cycle
D27–24 CE7WAIT
[3:0]
#CE7 static wait cycle
CE7WAIT[3:0]
Wait cycle
0xf R/W
0xf
0xe
:
0x1
0x0
15 cycles
14 cycles
:
1 cycle
0 cycles
D23–16 –
reserved
–
–
–
1 when being read.
D15–14 CE5SETUP
[1:0]
#CE5 setup cycle
CE5SETUP[1:0] Setup cycle
0x3 R/W
0x3
:
0x0
4 cycles
:
1 cycle
D13–12 CE5HOLD
[1:0]
#CE5 hold cycle
CE5HOLD[1:0]
Hold cycle
0x3 R/W
0x3
:
0x0
4 cycles
:
1 cycle
D11–8 CE5WAIT
[3:0]
#CE5 static wait cycle
CE5WAIT[3:0]
Wait cycle
0xf R/W
0xf
:
0x0
15 cycles
:
0 cycles
D7–6 CE4SETUP
[1:0]
#CE4 setup cycle
CE4SETUP[1:0] Setup cycle
0x3 R/W
0x3
:
0x0
4 cycles
:
1 cycle