DR
AFT
DR
AFT
DRAFT
DR
D
RAFT
DRAFT
DRA
FT DRAF
D
RAFT DRAFT DRAFT DRAFT DRAFT D
DRAFT
D
RAFT DRA
FT DRAFT DRAFT DRAFT DRA
UM10316_0
© NXP B.V. 2008. All rights reserved.
User manual
Rev. 00.06 — 17 December 2008
502 of 571
NXP Semiconductors
UM10316
Chapter 28: LPC29xx Flash/EEPROM
3.18 EEPROM signature register
The EEPROM BIST signature register returns the signatures as produced by the
embedded signature generators.
4.
Flash and EEPROM programming details
4.1 AHB programming
Programming an embedded flash memory is more complex than just writing data to the
appropriate address, like e.g. for embedded SRAM.
A flash memory is organized in sectors that must be erased before data can be written
into them. A flash memory also has sector protection.
programming flow chart. The part on the dark background is automatically done by the
flash hardware.
Flash programming contains the following elements.
•
unprotecting
•
erasing
Table 435. EEPROM BIST stop address register bit description (EEMSSTOP - address 0x2020 00A0)
Bits
Access Reset
value
Field name
Description
x:0
R/W
0x0
STOPA
BIST stop address:
Bit 0 is fixed zero since only even addresses are allowed.
The width of this field depends on the number of EEPROM devices:
1 EEPROM device => x = 13 (8 MSB, 0 CS and 6 LSB bits)
29:x+1 -
0x0
reserved
30
R/W
0x0
DEVSEL
BIST device select bit
0 : the BIST signature is generated over the total memory space. Singe pages are
interleaved over the EEPROM devices when multiple devices are used, the
signature is generated over memory of multiple devices.
1 : the BIST signature is generated only over a memory range located on a single
EEPROM device. Therefore the internal address generation is done such that the
address’ CS bits are kept stable to select only the same device. The address’
MSB and LSB bits are used to step through the memory range specified by the
start and stop address fields.
Note: if this bit is set the start and stop address fields must be programmed such
that they both address the same EEPROM device. Therefore the address’ CS
bits in both the start and stop address must be the same.
31
R/W
0x0
STRTBIST
BIST start bit
Setting this bit will start the BIST. This bit is self-clearing.
Table 436. EEPROM BIST signature register bit description (EEMSSIG - address 0x2020 00A4)
Bits
Access Reset
value
Field name
Description
15:0
R
0x0
DATA_SIG
BIST 16-bit signature calculated from only the data bytes
31:16
R
0x0
PARITY_SIG
BIST 16-bit signature calculated from only the parity bits of the data bytes