ATSAM3U-EK Atmel, ATSAM3U-EK Datasheet - Page 364

• Manufacturer Part Number: ATSAM3U-EK
• Description: KIT EVAL FOR AT91SAM3U CORTEX
• Manufacturer: Atmel
• Type: MCUr

Specifications of ATSAM3U-EK

• Contents: Board
• Processor To Be Evaluated: SAM3U
• Data Bus Width: 32 bit
• Interface Type: RS-232, USB
• Operating Supply Voltage: 3 V
• Silicon Manufacturer: Atmel
• Core Architecture: ARM
• Core Sub-architecture: Cortex - M3
• Silicon Core Number: SAM3U4E
• Silicon Family Name: SAM3U
• Kit Contents: Board CD Docs
• Rohs Compliant: Yes
• For Use With/related Products: AT91SAM3U
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

25.10.3.3
25.10.4
25.10.4.1
Figure 25-11. WRITE_MODE = 1. The write operation is controlled by NWE
25.10.4.2
364
364
SAM3U Series
SAM3U Series
Write Mode
Write Cycle
Write is Controlled by NWE (WRITE_MODE = 1)
Write is Controlled by NCS (WRITE_MODE = 0)
NWR0, NWR1
NBS0, NBS1,
A0, A1
D[15:0]
A [23:2]
NWE,
MCK
NCS
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
The WRITE_MODE parameter in the SMC_MODE register of the corresponding chip select indi-
cates which signal controls the write operation.
Figure 25-11
put on the bus during the pulse and hold steps of the NWE signal. The internal data buffers are
turned out after the NWE_SETUP time, and until the end of the write cycle, regardless of the
programmed waveform on NCS.
Figure 25-12
put on the bus during the pulse and hold steps of the NCS signal. The internal data buffers are
turned out after the NCS_WR_SETUP time, and until the end of the write cycle, regardless of
the programmed waveform on NWE.
shows the waveforms of a write operation with WRITE_MODE set to 1. The data is
shows the waveforms of a write operation with WRITE_MODE set to 0. The data is
6430D–ATARM–25-Mar-11
6430D–ATARM–25-Mar-11