ATEVK1104 Atmel, ATEVK1104 Datasheet - Page 379

• Manufacturer Part Number: ATEVK1104
• Description: KIT DEV/EVAL FOR AVR32 AT32UC3A
• Manufacturer: Atmel
• Series: AVR®32r
• Type: MCUr

Specifications of ATEVK1104

• Contents: Evaluation Board, Software and Documentation
• Processor To Be Evaluated: AT32UC3A3
• Data Bus Width: 32 bit
• Interface Type: USB, SPI, USART
• Silicon Manufacturer: Atmel
• Core Architecture: AVR
• Core Sub-architecture: AVR UC3
• Silicon Core Number: AT32UC3A3256
• Silicon Family Name: AVR
• Kit Contents: Board CD Docs
• Rohs Compliant: Yes
• For Use With/related Products: AT32UC3A3
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

32058J–AVR32–04/11
– Write Cycle
– Null Delay Setup and Hold
Figure 27-13. Write Cycle
The write_cycle time is defined as the total duration of the write cycle, that is, from the time
where address is set on the address bus to the point where address may change. The total write
cycle time is equal to:
NWE_CYCLE = NWE_SETUP + NWE_PULSE + NWE_HOLD
= NCS_WR_SETUP + NCS_WR_PULSE + NCS_WR_HOLD
All NWE and NCS (write) timings are defined separately for each chip select as an integer num-
ber of Master Clock cycles. To ensure that the NWE and NCS timings are coherent, the user
must define the total write cycle instead of the hold timing. This implicitly defines the NWE hold
time and NCS (write) hold times as:
NWE_HOLD = NWE_CYCLE - NWE_SETUP - NWE_PULSE
NCS_WR_HOLD = NWE_CYCLE - NCS_WR_SETUP - NCS_WR_PULSE
If null setup parameters are programmed for NWE and/or NCS, NWE and/or NCS remain active
continuously in case of consecutive write cycles in the same memory (see
ever, for devices that perform write operations on the rising edge of NWE or NCS, such as
SRAM, either a setup or a hold must be programmed.
NBS0, NBS1,
A0, A1
CLK_SMC
A[25:2]
NWE
NCS
NCS_WR_SETUP
NWE_SETUP
NCS_WR_PULSE
NWE_CYCLE
NWE_PULSE
NWE_HOLD
NCS_WR_HOLD
AT32UC3A
Figure
27-14). How-
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