DV164122 Microchip Technology, DV164122 Datasheet - Page 80

• Manufacturer Part Number: DV164122
• Description: ANALYZER SRL PICKIT W/DEMO BOARD
• Manufacturer: Microchip Technology
• Series: PICkit™r
• Type: MCUr

Specifications of DV164122

• Contents: PICkit™ Serial Analyzer, 28-pin Demo Board, USB Cable, and Software with Documentation CD
• Processor To Be Evaluated: PIC16F886
• Interface Type: USB
• Silicon Manufacturer: Microchip
• Kit Application Type: Interface
• Application Sub Type: USB
• Silicon Family Name: PIC16F
• Kit Contents: PICkit Serial Analyzer, Demo Board, USB Cable, Software
• Rohs Compliant: Yes
• Lead Free Status / RoHS Status: Not applicable / Not applicable
• For Use With/related Products: PIC16F886
• For Use With: PKSERIAL-SPI1 - BOARD DEMO PICKIT SERIAL SPIPKSERIAL-I2C1 - BOARD DEMO PICKIT SERIAL I2C
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant
• Other names: Q3260228

PICkit™ Serial Analyzer User’s Guide
DS51647A-page 74
EXEC manages the interface with the host. The data stream sent to PICkit™ Serial
Analyzer from the host is encoded with ECMD TAGs and the data stream returned to
the host from PICkit™ Serial Analyzer uses EDATA TAGs. Likewise, the COMM con-
troller utilizes another set of predefined TAG(s) - CCMD TAGs (outgoing scripts) and
CDATA TAGs (returning data). EXEC has no knowledge of COMM TAG(s) but simply
transports data blindly between the host and COMM using EXEC TAG(s). RAM buffers
are used as conduits to exchange data with COMM. Data destined for COMM is
queued in RAM buffer 1 (CBUF1). Data returning from COMM is funneled through RAM
buffer 2 (CBUF2).
The PICkit™ Serial Analyzer is designed to facilitate continuous ‘spooling’ of data
to/from the external serial device. Separate 255-byte circular buffers are maintained for
both outgoing data (scripts/data) and returning data. The USB interface is not permitted
to be a bottleneck in the PICkit™ Serial Analyzer operation. EXEC processes each
USB packet immediately. If data is destined for a RAM buffer, the host is responsible to
insure adequate room is available in the buffer before the data is sent to avoid a fatal
‘overrun’ error. Returning data is queued in the appropriate circular buffer until retrieved
by EXEC, tagged and sent to the host. It is possible to overrun the return buffer under
some circumstances but should be rare. EXEC can interleave EXEC data with COMM
data as necessary.
The PICkit™ Serial Analyzer maintains fixed-length blocks of data for CONTROL and
STATUS. The CONTROL_BLOCK provides ‘static’ configuration information. The
STATUS_BLOCK is a snapshot of the PICkit™ Serial Analyzer operation. Each block
is divided into three sections corresponding to EXEC, COMM (common to all protocols)
and COMM (specific to the active serial protocol).
TABLE 9-1:
The other major blocks are the control memory block and the status memory block. The
control block is used to configure the PICkit™ Serial Analyzer. The control block is
divided into the following three sections:
• EXEC module configuration
• Generic COMM module configuration
• Protocol specific communication configuration
This third section will change depending on the protocol. The Status block keeps the
status of various flags and is similarly divided into three sections.
TABLE 9-2:
ECMD
EDATA
CCMD
CDATA
0-7
8-15
16-23
TAG types
TAG Bytes
TAG BYTE TYPES
CONTROL BLOCK
EXEC command TAG(s) – interpreted by EXEC
EXEC data TAG(s) – generated by EXEC
COMM command TAG)(s) – interpreted by COMM
COMM data TAG(s) – generated by COMM
EXEC section
Generic COMM section
Protocol specific communication section
Definition
Definition
© 2007 Microchip Technology Inc.