29 MISC REGISTERS (MISC)
29-4
Seiko Epson Corporation
S1C33L26 TECHNICAL MANUAL
D5
USBSNZ: USB Snooze Control Bit
Enables or disables the USB to enter snooze mode.
1 (R/W): Enabled
0 (R/W): Disabled (default)
When this bit is set to 1, the USB controller performs a transition sequence and then it enters Snooze
mode. When this bit is set to 0, the USB controller resumes operating. For details of the snooze se-
quence, see the “Snooze” section in the “USB Function Controller (USB)” chapter.
D[4:3]
Reserved
D[2:0]
USBWT[2:0]: USB Register Access Wait Control Bits
Sets the number of wait cycles to be inserted when accessing the USB control register.
6.3 USBWT[2:0] (USB Wait Cycle) Settings
Table 29.
USBWT[2:0]
Number of wait cycles
MCLK frequency
0x7
7 cycles
f
MCLK
≤
60 MHz
0x6
6 cycles
f
MCLK
≤
56 MHz
0x5
5 cycles
f
MCLK
≤
45 MHz
0x4
4 cycles
f
MCLK
≤
36 MHz
0x3
3 cycles
f
MCLK
≤
24 MHz
0x2
2 cycles
f
MCLK
≤
16 MHz
0x1
1 cycle
f
MCLK
< 8 MHz
0x0
0 cycles
(Default: 0x7)
The number of wait cycles should be set according to the MCLK clock frequency.
Internal RAM Wait Control Register (MISC_RAMWT)
Register name Address
Bit
Name
Function
Setting
Init. R/W
Remarks
Internal RAM
Wait Control
Register
(MISC_RAMWT)
0x300014
(8 bits)
D7–2 –
reserved
–
–
–
0 when being read.
D1
COREWT
IRAM (12KB) access wait control
1 1 cycle
0 0 cycles
1
R/W Write-protected
D0
BUSWT
IVRAM (20KB) access wait control 1 1 cycle
0 0 cycles
1
R/W
D[7:2]
Reserved
D1
COREWT: IRAM (12KB) Access Wait Control Bit
Sets the number of wait cycles to be inserted when accessing IRAM (Area 0).
1 (R/W): 1 cycle (default)
0 (R/W): 0 cycles (no wait inserted)
6.4 COREWT (IRAM Wait Cycle) Settings
Table 29.
COREWT
Number of wait cycles
MCLK frequency
1
1 cycle
f
MCLK
≤
60 MHz
0
0 cycles
D0
BUSWT: IVRAM (20KB) Access Wait Control Bit
Sets the number of wait cycles to be inserted when accessing IVRAM (Area 3).
1 (R/W): 1 cycle (default)
0 (R/W): 0 cycles (no wait inserted)
If IVRAM is relocated to Area 0, the COREWT setting is ineffective.
6.5 BUSWT (IVRAM Wait Cycle) Settings
Table 29.
BUSWT
Number of wait cycles
MCLK frequency
1
1 cycle
f
MCLK
≤
60 MHz
0
0 cycles