Atmel ARM-Based Evaluation Kit for SAM4S16C, 32-Bit ARM® Cortex® Microcontroller ATSAM4S-WPIR-RD ATSAM4S-WPIR-RD Data Sheet

Product codes

ATSAM4S-WPIR-RD

SAM4S Series [DATASHEET]

Atmel-11100G-ATARM-SAM4S-Datasheet_27-May-14

374

21.3.3 Entering Programming Mode

The following algorithm puts the device in Parallel Programming Mode:



Apply the supplies as described in

Table 21-1



Apply XIN clock within T

POR_RESET

if an external clock is available.



Wait for T

POR_RESET



Start a read or write handshaking.

Note:

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.

21.3.4 Programmer Handshaking

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.

21.3.4.1 Write Handshaking

For details on the write handshaking sequence, refer to

Figure 21-2

Figure 21-3

and

Table 21-4

Figure 21-2.

Parallel Programming Timing, Write Sequence

0x0025

GGPB

Get General Purpose NVM bit

0x0054

SSE

Set Security Bit

0x0035

GSE

Get Security Bit

0x001F

WRAM

Write Memory

0x001E

GVE

Get Version

Table 21-3.

Command Bit Coding (Continued)

DATA[15:0]

Symbol

Command Executed

NCMD

RDY

NOE

NVALID

DATA[15:0]

MODE[3:0]