W78LE516 Datasheet, PDF (11/31 Pages) Winbond – 8-BIT MICROCONTROLLER

Preliminary W78LE516
Here is an example to program the P4.0 as a write strobe signal at the I/O port address
1234H−1237H and positive polarity, and P4.1−P4.3 are used as general I/O ports.
MOV P40AH,#12H
MOV P40AL,#34H
MOV P4CONA,#00001010B
MOV P4CONB,#00H
MOV P2ECON,#10H
MOV CHPENR,#00H
; Base I/O address 1234H for P4.0
; P4.0 a write strobe signal and address line A0 and A1 are masked.
; P4.1−P4.3 as general I/O port which are the same as PORT1
; Write the P40SINV = 1 to inverse the P4.0 write strobe polarity
; default is negative.
; Disable CHPCON write attribute.
Then any instruction MOVX @DPTR,A (with DPTR = 1234H−1237H) will generate the positive
polarity write strobe signal at pin P4.0. And the instruction MOV P4,#XX will output the bit3 to bit1 of
data #XX to pin P4.3−P4.1.
P4 REGISTER
P4.x
READ
WRITE
P4xCSINV
DATA I/O
RD_CS
MUX 4->1
WR_CS
RD/WR_CS
ADDRESS BUS
EQUAL
REGISTER
P4xAL
P4xAH
Bit Length
Selectable
comparator
REGISTER
P4xCMP0
P4xCMP1
P4xFUN0
P4xFUN1
P4.x INPUT DATA BUS
PIN
P4.x
In-System Programming (ISP) Mode
The W78LE516 equips one 64K byte of main MTP-ROM bank for application program (called
APROM) and one 4K byte of auxiliary MTP-ROM bank for loader program (called LDROM). In the
normal operation, the microcontroller executes the code in the APROM. If the content of APROM
needs to be modified, the W78LE516 allows user to activate the In-System Programming (ISP) mode
by setting the CHPCON register. The CHPCON is read-only by default, software must write two
specific values 87H, then 59H sequentially to the CHPENR register to enable the CHPCON
write attribute. Writing CHPENR register with the values except 87H and 59H will close
CHPCON register write attribute. The W78LE516 achieves all in-system programming operations
including enter/exit ISP Mode, program, erase, read ... etc, during device in the idle mode. Setting the
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Publication Release Date: June 2000
Revision A1