XC2200 Derivatives
System Units (Vol. 1 of 2)
Memory Organization
User’s Manual
3-27
V2.1, 2008-08
MemoryX2K, V1.3
The argument “MR” defines the read margin:
•
00
H
: normal read margin.
•
01
H
: hard read 0 margin.
•
02
H
: alternate hard read 0 margin.
•
05
H
: hard read 1 margin.
•
06
H
: alternate hard read 1 margin.
•
Other values: reserved.
For understanding the read margins please refer to
.
This command must not be issued when the flash memory is in page mode. In this case
it is ignored and a sequence error is reported.
”, “
”, “
” and “
” reset the read
margin back to 00
H
, i.e. to the normal read margin. The same happens in case of
a flash wake-up.
Enter Page Mode
Arguments: PA
Definition:
MOV XXAA
H
, XX50
H
MOV PA, XXAA
H
Timing: 2-cycle command that sets “BUSY” for around 100 clock cycles.
Description: The page mode is entered to prepare a page programming operation on
page address PA. (Write data are accepted only with the “
” command.)
With this command, the IMB Core initializes the write pointer of its block assembly
register to zero so that it points to the first word. The page mode is indicated in the status
register IMB_FSR with the PAGE bit, separately for each flash module. The page mode
and the read mode are allowed in parallel at the same time and in the same flash module
so the flash module stays readable. When the addressed page PA is read the content of
the flash memory is delivered. The page mode can be aborted and the related PAGE bit
in IMB_FSR be cleared with the “
” command. A new “
command during page mode aborts the actual page mode, which is indicated with the
error flag SQER, and restarts a new page operation. So as mentioned above only one
of the flash modules can be in page mode at a time. If one of the erase commands or the
“
” command are received while in page mode it is ignored and a
sequence error is reported.
If write protection is installed for the sector to be programmed, the “
command is only accepted when write protection has before been disabled using the
unlock command sequence “
” with four passwords. If global
write protection is installed with read protection, also the command “
” can be used if no sector specific protection is installed. If write protection is