X88C75 Datasheet, PDF (6/27 Pages) Xicor Inc. – Port Expander and E2 Memory

X88C75 SLIC^® E²
that accessing the BPR automatically sets the upper
level SDP. If for some reason the user does not want
SDP enabled, they may reset it using the normal reset
command sequence. This will not affect the state of the
BPR and any 1K x 8 blocks that were set to the write
lockout state will remain in the write lockout state.
Figure 4. Block Protect Register Format
MSB
LSB
7 6543210
BLOCK
ADDRESS
0000-03FF
0400-07FF
0800-0BFF
0C00-0FFF
1000-13FF
1400-17FF
1800-1BFF
1C00-1FFF
“1” = Protect, “0” = Unprotect Block Specified
2887 ILL F08.1
Figure 5. Setting BPR Command Sequence
AA
b2 b1 b0 P 555
55
b2 b1 b0 P AAA
A0
b2 b1 b0 P 555
AA
b2 b1 b0 P 555
C0
b2 b1 b0 P AAA
Write BPR mask value
to any address
Delay of t_WC
The BPR format and block map are illustrated above.
The command sequence is illustrated to the right.
Figure 6. Microcontroller Map
Exit Routine
2887 ILL F09.1
(BPR Register Set Global SDP Set)
b2
b1
b0
Reference the A15–A13
setting in E2M register
P = Address bit (A12) of the
memory plane not being read.
0000
1FFF
0000
0030
0150
RESET/ISR VECTORS
SLIC
USER
APPLICATION
CODE/DATA
8K BYTES OF BYTE
ALTERABLE DUAL
PLANE ARCHITECTURED
NON-VOLATILE MEMORY
(MAPPABLE TO ANY 8K
PAGE BY THE E2M BITS 2–0)
1F00
1FFF
SLIC
FFFF
FC00
FFFF
6
SRF (SPECIAL FUNCTION
REGISTER) BLOCK
(MAPPABLE TO ANY 1K
PAGE BY THE SFRM
REGISTER)
2887 ILL F29.1