ATEVK1105 Atmel, ATEVK1105 Datasheet - Page 376

• 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

27.6.4.2
32058J–AVR32–04/11
– Null Pulse
– Read is Controlled by NRD (READ_MODE = 1):
Read Mode
Figure 27-10. No Setup, No Hold On NRD and NCS Read Signals
Programming null pulse is not permitted. Pulse must be at least set to 1. A null value leads to
unpredictable behavior.
As NCS and NRD waveforms are defined independently of one other, the SMC needs to know
when the read data is available on the data bus. The SMC does not compare NCS and NRD tim-
ings to know which signal rises first. The READ_MODE parameter in the MODE register of the
corresponding chip select indicates which signal of NRD and NCS controls the read operation.
Figure 27-11
read data is available t
NRD. In this case, the READ_MODE must be set to 1 (read is controlled by NRD), to indicate
that data is available with the rising edge of NRD. The SMC samples the read data internally on
the rising edge of Master Clock that generates the rising edge of NRD, whatever the pro-
grammed waveform of NCS may be.
NBS0, NBS1,
A0, A1
CLK_SMC
A[25:2]
D[15:0]
NRD
NCS
shows the waveforms of a read operation of a typical asynchronous RAM. The
PACC
NCS_RD_PULSE
NRD_CYCLE
NRD_SETUP
after the falling edge of NRD, and turns to ‘Z’ after the rising edge of
NCS_RD_PULSE
NRD_CYCLE
NRD_PULSE
NCS_RD_PULSE
NRD_CYCLE
NRD_PULSE
AT32UC3A
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