Microchip Technology DV164136 Data Sheet
2007-2012 Microchip Technology Inc.
DS39778E-page 109
PIC18F87J11 FAMILY
8.6.1
16-BIT BYTE WRITE MODE
shows an example of 16-Bit Byte Write
mode for PIC18F87J11 family devices. This mode is
used for two separate 8-bit memories connected for
16-bit operation. This generally includes basic EPROM
and Flash devices; it allows table writes to byte-wide
external memories.
used for two separate 8-bit memories connected for
16-bit operation. This generally includes basic EPROM
and Flash devices; it allows table writes to byte-wide
external memories.
During a TBLWT instruction cycle, the TABLAT data is
presented on the upper and lower bytes of the
AD<15:0> bus. The appropriate WRH or WRL control
line is strobed on the LSb of the TBLPTR.
presented on the upper and lower bytes of the
AD<15:0> bus. The appropriate WRH or WRL control
line is strobed on the LSb of the TBLPTR.
FIGURE 8-1:
16-BIT BYTE WRITE MODE EXAMPLE
AD<7:0>
A<19:16>
(1)
ALE
D<15:8>
373
A<x:0>
D<7:0>
A<19:0>
A<x:0>
D<7:0>
373
OE
WRH
OE
OE
WR
(2)
WR
(2)
CE
CE
Note
1:
Upper order address lines are used only for 20-bit address widths.
2:
This signal only applies to table writes. See
.
WRL
D<7:0>
(LSB)
(MSB)
PIC18F87J11
D<7:0>
AD<15:8>
Address Bus
Data Bus
Control Lines
Data Bus
Control Lines
CE