SAM3N00A Atmel Corporation, SAM3N00A Datasheet - Page 294

• Manufacturer Part Number: SAM3N00A
• Manufacturer: Atmel Corporation

19.2.3
19.2.4
19.2.4.1
294
SAM3N
Entering Programming Mode
Programmer Handshaking
Write Handshaking
The following algorithm puts the device in Parallel Programming Mode:
Note:
An handshake is defined for read and write operations. When the device is ready to start a new
operation (RDY signal set), the programmer starts the handshake by clearing the NCMD signal.
The handshaking is achieved once NCMD signal is high and RDY is high.
For details on the write handshaking sequence, refer to
Figure 19-3. SAM3NxB/C (64/100 pins) Parallel Programming Timing, Write Sequence
• Apply GND, VDDIO, VDDCORE and VDDPLL.
• Apply XIN clock within T
• Wait for T
• Start a read or write handshaking.
After reset, the device is clocked by the internal RC oscillator. Before clearing RDY signal, if an
external clock ( > 32 kHz) is connected to XIN, then the device switches on the external clock.
Else, XIN input is not considered. A higher frequency on XIN speeds up the programmer
handshake.
MODE[3:0]
DATA[7:0]
POR_RESET
NVALID
NCMD
NOE
RDY
1
2
POR_RESET
3
if an external clock is available.
Figure 19-3 Figure 19-4
4
5
11011A–ATARM–04-Oct-10
and
Table
19-4.