MA180023 Microchip Technology, MA180023 Datasheet - Page 176

• Manufacturer Part Number: MA180023
• Description: MODULE PLUG-IN PIC18F46J11 PIM
• Manufacturer: Microchip Technology
• Series: PIC®r

Specifications of MA180023

• Accessory Type: Plug-In Module (PIM) - PIC18F46J11
• Tool / Board Applications: General Purpose MCU, MPU, DSP, DSC
• Mcu Supported Families: PIC18
• Supported Devices: Stand-alone Or W/ HPC(DM183022) Or PIC18(DM183032)
• Silicon Manufacturer: Microchip
• Core Architecture: PIC
• Core Sub-architecture: PIC18
• Silicon Core Number: PIC18F
• Silicon Family Name: PIC18FxxJxx
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• For Use With/related Products: HPC Explorer Board (DM183022) or PIC18 Explorer Board (DM183032)
• For Use With: DM183032 - BOARD EXPLORER PICDEM PIC18DM183022 - BOARD DEMO PIC18FXX22 64/80TQFP
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

PIC18F46J11 FAMILY
10.2.4
Buffered Parallel Slave Port mode is functionally
identical to the legacy PSP mode with one exception,
the implementation of 4-level read and write buffers.
Buffered PSP mode is enabled by setting the INCM bits
in the PMMODEH register. If the INCM<1:0> bits are
set to ‘11’, the PMP module will act as the Buffered
PSP.
When the Buffered mode is active, the PMDIN1L,
PMDIN1H, PMDIN2L and PMDIN2H registers become
the write buffers and the PMDOUT1L, PMDOUT1H,
PMDOUT2L and PMDOUT2H registers become the
read buffers. Buffers are numbered 0 through 3, start-
ing with the lower byte of PMDIN1L to PMDIN2H as the
read buffers and PMDOUT1L to PMDOUT2H as the
write buffers.
10.2.4.1
For read operations, the bytes will be sent out
sequentially, starting with Buffer 0 (PMDOUT1L<7:0>)
and ending with Buffer 3 (PMDOUT2H<7:0>) for every
read strobe. The module maintains an internal pointer
to keep track of which buffer is to be read. Each buffer
has a corresponding read status bit, OBxE, in the
PMSTATL register. This bit is cleared when a buffer
contains data that has not been written to the bus, and
is set when data is written to the bus. If the current buf-
fer location being read from is empty, a buffer underflow
is generated, and the Buffer Overflow flag bit, OBUF, is
set. If all four OBxE status bits are set, then the Output
Buffer Empty flag (OBE) will also be set.
FIGURE 10-5:
DS39932C-page 176
Master
PMD<7:0>
BUFFERED PARALLEL SLAVE
PORT MODE
PMCS1
PMWR
PMRD
READ FROM SLAVE PORT
PARALLEL MASTER/SLAVE CONNECTION BUFFERED EXAMPLE
Data Bus
Control Lines
PMD<7:0>
PMCS
PMRD
PMWR
10.2.4.2
For write operations, the data has to be stored
sequentially, starting with Buffer 0 (PMDIN1L<7:0>)
and ending with Buffer 3 (PMDIN2H<7:0>). As with
read operations, the module maintains an internal
pointer to the buffer that is to be written next.
The input buffers have their own write status bits, IBxF
in the PMSTATH register. The bit is set when the buffer
contains unread incoming data, and cleared when the
data has been read. The flag bit is set on the write
strobe. If a write occurs on a buffer when its associated
IBxF bit is set, the Buffer Overflow flag, IBOV, is set;
any incoming data in the buffer will be lost. If all four
IBxF flags are set, the Input Buffer Full Flag (IBF) is set.
In Buffered Slave mode, the module can be configured
to generate an interrupt on every read or write strobe
(IRQM<1:0> = 01). It can be configured to generate an
interrupt on a read from Read Buffer 3 or a write to
Write Buffer 3, which is essentially an interrupt every
fourth read or write strobe (RQM<1:0> = 11). When
interrupting every fourth byte for input data, all input
buffer registers should be read to clear the IBxF flags.
If these flags are not cleared, then there is a risk of
hitting an overflow condition.
Address
Pointer
Write
PMDOUT1H (1)
PMDOUT2H (3)
PMDOUT1L (0)
PMDOUT2L (2)
PIC18 Slave
WRITE TO SLAVE PORT
© 2009 Microchip Technology Inc.
Address
Pointer
Read
PMDIN1H (1)
PMDIN2H (3)
PMDIN1L (0)
PMDIN2L (2)