upd70f3422gj-gae-qs-ax Renesas Electronics Corporation., upd70f3422gj-gae-qs-ax Datasheet - Page 879

• Manufacturer Part Number: upd70f3422gj-gae-qs-ax
• Description: 32-bit Single-chip Microcontroller
• Manufacturer: Renesas Electronics Corporation.

On-Chip Debug Unit
Security bit
Caution
ID code
28.1.2 Security function
This microcontroller has a N-Wire security function, that demands the user to
input an ID code upon start of the debugger. The ID code is compared to a
predefined ID code, written in advance to the internal flash memory by an
external flash programmer. This function prevents unauthorized persons to
operate the microcontroller in N-Wire debug mode and to read the internal
flash memory area.
The ID code in the internal flash memory can only be written by an external
flash programmer. It can’t be changed in self-programming mode and therefore
also not in N-Wire debugging mode.
Be sure to write an ID code when writing a program to the internal flash
memory.
The area of the ID code is 10 bytes wide and in the range of addresses
0000 0070
The ID code when the memory is erased is shown below.
Bit 7 of address 0000 0079
• Bit 7 of address 0000 0079
This security bit can only be modified by programming the flash memory via an
external flash programmer. It is not possible to modify the security bit in self-
programming mode, and therefore also not in N-Wire debugging mode.
After reset the entire ID code area is set to FF
• N-Wire debugging is generally enabled
• the ID code is FF
Consequently controller access is possible without any restriction.
If access via the N-Wire interface should be disabled "block erase disabled"
should be configured as well. Otherwise the flash memory blocks containing
the ID code could be erased and N-Wire access could be enabled.
Preliminary User’s Manual U17566EE1V2UM00
Address
0000 0079
0000 0078
0000 0077
0000 0076
0000 0075
0000 0074
0000 0073
0000 0072
0000 0071
0000 0070
0: disabled N-Wire emulator cannot connect to the on-chip debug unit.
1: enabled N-Wire emulator can connect to the on-chip debug unit if the
H
H
H
H
H
H
H
H
H
H
H
to 0000 0079
10-byte ID code input matches the ID code stored in the flash
memory
H
for all ID code bytes
H
H
.
enables or disables use of the N-Wire emulator.
H
ID code
FF
FF
FF
FF
FF
FF
FF
FF
FF
FF
H
H
H
H
H
H
H
H
H
H
H
. This means that
Chapter 28
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