Datasheet

PIC18F87J50 FAMILY
DS39775C-page 178 © 2009 Microchip Technology Inc.
11.2.5 ADDRESSABLE PARALLEL SLAVE
PORT MODE
In the Addressable Parallel Slave Port mode
(PMMODEH<1:0> = 01), the module is configured with
two extra inputs, PMA<1:0>, which are the address
lines 1 and 0. This makes the 4-byte buffer space
directly addressable as fixed pairs of read and write
buffers. As with legacy Buffered mode, data is output
from PMDOUT1L, PMDOUT1H, PMDOUT2L and
PMDOUT2H, and is read in PMDIN1L, PMDIN1H,
PMDIN2L and PMDIN2H. Table 11-2 shows the buffer
addressing for the incoming address to the input and
output registers.
TABLE 11-2: SLAVE MODE BUFFER
ADDRESSING
FIGURE 11-6: PARALLEL MASTER/SLAVE CONNECTION ADDRESSED BUFFER EXAMPLE
PMADDR<1:0>
Output
Register
(Buffer)
Input Register
(Buffer)
00 PMDOUT1L (0) PMDIN1L (0)
01 PMDOUT1H (1) PMDIN1H (1)
10 PMDOUT2L (2) PMDIN2L (2)
11 PMDOUT2H((3) PMDIN2H (3)
PMD<7:0>
PMRD
PMWR
Master
PMCS
PMA<1:0>
Address Bus
Data Bus
Control Lines
PMRD
PMWR
PIC18F Slave
PMCS1
PMDOUT1L (0)
PMDOUT1H (1)
PMDOUT2L (2)
PMDOUT2H (3)
PMDIN1L (0)
PMDIN1H (1)
PMDIN2L (2)
PMDIN2H (3)
PMD<7:0>
Write
Address
Decode
Read
Address
Decode
PMA<1:0>