
Semiconductor Group 3 - 17
Memory Organization
Table 3-3: Behaviour of P0/P2 and RD/WR During MOVX Accesses
EA
= 0 EA = 1
XMAP1, XMAP0 XMAP1, XMAP0
00 10 X1 00 10 X1
MOVX
@DPTR
DPTR
<
XRAM
address
range
a)P0/P2→Bus
b)RD
/WR active
c)ext.memory
is used
a)P0/P2→Bus
b)RD
/WR active
c)ext.memory
is used
a)P0/P2→Bus
b)RD
/WR active
c)ext.memory
is used
a)P0/P2→Bus
b)RD
/WR active
c)ext.memory
is used
a)P0/P2→Bus
b)RD
/WR active
c)ext.memory
is used
a)P0/P2→Bus
b)RD
/WR active
c)ext.memory
is used
DPTR
≥
XRAM
address
range
a)P0/P2
→Bus
(WR
-Data only)
b)RD
/WR
inactive
c)XRAM is used
a)P0/P2
→Bus
(WR
-Data only)
b)RD
/WR active
c)XRAM is used
a)P0/P2→Bus
b)RD
/WR active
c) ext.memory
is used
a)P0/P2
→I/O
b)RD
/WR
inactive
c)XRAM is used
a)P0/P2
→Bus
(WR
-Data only)
b)RD
/WR active
c)XRAM is used
a)P0/P2→Bus
b)RD
/WR active
c) ext.memory
is used
MOVX
@ Ri
XPAGE
<
XRAM
addr.page
range
a)P0→Bus
P2
→I/O
b)RD
/WR active
c)ext.memory
is used
a)P0→Bus
P2
→I/O
b)RD
/WR active
c)ext.memory
is used
a)P0→Bus
P2
→I/O
b)RD
/WR active
c)ext.memory
is used
a)P0→Bus
P2
→I/O
b)RD
/WR active
c)ext.memory
is used
a)P0→Bus
P2
→I/O
b)RD
/WR active
c)ext.memory
is used
a)P0→Bus
P2
→I/O
b)RD
/WR active
c)ext.memory
is used
XPAGE
≥
XRAM
addr.page
range
a)P0
→Bus
(WR
-Data only)
P2
→I/O
b)RD
/WR
inactive
c)XRAM is used
a)P0
→Bus
(WR
-Data only)
P2
→I/O
b)RD
/WR active
c)XRAM is used
a)P0→Bus
P2
→I/O
b)RD
/WR active
c)ext.memory
is used
a)P0/P2
→I/O
b)RD
/WR
inactive
c)XRAM is used
a)P0
→Bus
(WR
-Data only)
P2
→I/O
b)RD
/WR active
c)XRAM is used
a)P0→Bus
P2
→I/O
b)RD
/WR active
c)ext.memory
is used
modes compatible to 8051-family
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