at91sam9g20-cu ATMEL Corporation, at91sam9g20-cu Datasheet - Page 764

• Manufacturer Part Number: at91sam9g20-cu
• Description: At91 Arm Thumb Microcontrollers
• Manufacturer: ATMEL Corporation

41.4.4
764
AT91SAM9G20 Preliminary
I/O Slew Rates
The IOSR and VDDIOMSEL bits in the EBI_CSA register allow the user to program the rising
and falling times of SDRAM signals. Rising/Falling time is given between 30% and 70%.
Table 41-7.
Table 41-8.
VDDIOMSEL
VDDIOMSEL
0
0
1
1
0
0
1
1
SDRAM Clock
SDRAM Data, Address and Control
IOSR
IOSR
0
1
0
1
0
1
0
1
1.8V range, FAST slew rate,
C
1.8V range, SLOW slew rate,
C
3.3V range, FAST slew rate,
C
C
1.8V range, FAST slew rate,
C
1.8V range, SLOW slew rate,
C
3.3V range, FAST slew rate,
C
C
Conditions
3.3V range, SLOW slew rate,
Conditions
3.3V range, SLOW slew rate,
LOAD
LOAD
LOAD
LOAD
LOAD
LOAD
LOAD
LOAD
= 10 pF
= 10 pF
= 10 pF
= 30 pF
= 30 pF
= 50 pF
= 50 pF
= 10 pF
Rising time
Rising time
(ns)
(ns)
0.8
1.6
0.8
1.5
1.5
1.7
2.8
6.0
6384B–ATARM–15-Dec-08
Falling time
Falling time
(ns)
(ns)
1.0
1.5
0.8
1.6
1.5
1.8
3.1
5.7