ATEVK1105 Atmel, ATEVK1105 Datasheet - Page 419

• Manufacturer Part Number: ATEVK1105
• Description: KIT EVAL FOR AT32UC3A0
• Manufacturer: Atmel
• Series: AVR®32r
• Type: MCUr

Specifications of ATEVK1105

• Contents: Evaluation Board, Software and Documentation
• Processor To Be Evaluated: AT32UC3A0512
• Processor Series: AVR
• Data Bus Width: 32 bit
• Interface Type: USART, TWI, USB, SPI, Ethernet
• Operating Supply Voltage: 3.3 V
• Silicon Manufacturer: Atmel
• Core Architecture: AVR
• Core Sub-architecture: AVR UC3
• Silicon Core Number: AT32UC3A0512
• Silicon Family Name: AVR
• Kit Contents: Board CD Docs
• Rohs Compliant: Yes
• For Use With/related Products: AT32UC3A0
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

Figure 28-7. Read Burst with Boundary Row Access
28.7.4
32058J–AVR32–04/11
SDRAMC_A[12:0]
D[31:0]
SDWE
SDCS
SDCK
RAS
CAS
SDRAM Controller Refresh Cycles
col a
Row n
col b
Dna
An auto-refresh command is used to refresh the SDRAM device. Refresh addresses are gener-
ated internally by the SDRAM device and incremented after each auto-refresh automatically.
The SDRAM Controller generates these auto-refresh commands periodically. An internal timer is
loaded with the value in the register TR that indicates the number of clock cycles between
refresh cycles.
A refresh error interrupt is generated when the previous auto-refresh command did not perform.
It is acknowledged by reading the Interrupt Status Register (ISR).
When the SDRAM Controller initiates a refresh of the SDRAM device, internal memory accesses
are not delayed. However, if the CPU tries to access the SDRAM, the slave indicates that the
device is busy and the master is held by a wait signal. See
col c
Dnb
col d
Dnc
Dnd
T
RP
= 3
Row m
T
RCD
= 3
col a
CAS = 2
Figure
col b
Dma
col c
28-8.
Dmb
col d
Dmc
AT32UC3A
col e
Dmd
Dme
419