DSPIC33F datasheet(48/80 Pages) MICROCHIP

48 / 80 page

dsPIC33F/PIC24H PROGRAMMING SPECIFICATION

DS70152D-page 48

Preliminary

FIGURE 4-2:

PROGRAMMING EXECUTIVE – PROGRAMMER COMMUNICATION PROTOCOL

4.2

Programming Executive

Commands

The programming executive command set is shown in

Table 4-1. This table contains the opcode, mnemonic,

length, time out and description for each command.

Functional details on each command are provided in

the command descriptions (Section 4.2.4 “Command

Descriptions”).

4.2.1

COMMAND FORMAT

All programming executive commands have a general

format consisting of a 16-bit header and any required

data for the command (see Figure 4-3). The 16-bit

header consists of a 4-bit opcode field, which is used to

identify the command, followed by a 12-bit command

length field.

FIGURE 4-3:

COMMAND FORMAT

The command opcode must match one of those in the

command set. Any command that is received which

does not match the list in Table 4-1 will return a “NACK”

response (see Section 5.3.1.1 “Opcode Field”).

The command length is represented in 16-bit words

since the SPI operates in 16-bit mode. The program-

ming executive uses the command length field to

determine the number of words to read from the SPI

port. If the value of this field is incorrect, the command

will not be properly received by the programming

executive.

4.2.2

PACKED DATA FORMAT

When 24-bit instruction words are transferred across

the 16-bit SPI interface, they are packed to conserve

space using the format shown in Figure 4-4. This

format minimizes traffic over the SPI and provides the

programming executive with data that is properly

aligned for performing table write operations.

FIGURE 4-4:

PACKED INSTRUCTION

WORD FORMAT

4.2.3

PROGRAMMING EXECUTIVE

ERROR HANDLING

The

programming

executive

will

“NACK”

all

unsupported commands. Additionally, due to the

memory constraints of the programming executive, no

checking is performed on the data contained in the

programmer command. It is the responsibility of the

programmer to command the programming executive

with valid command arguments or the programming

operation may fail. Additional information on error

handling is provided in Section 5.3.1.3 “QE_Code

Field”.

15 16

PGC

PGD

PGC = Input

PGC = Input (Idle)

Host Transmits

Last Command Word

PGD = Input

PGD = Output

15 16

MSB X X X LSB

P9b

PGC = Input

PGD = Output

P9a

Programming Executive

Processes Command

Host Clocks Out Response

8ns

23 µs

Opcode

Length

Command Data First Word (if required)

•

Command Data Last Word (if required)

Note:

When the number of instruction words

transferred is odd, MSB2 is zero and

LSW2 can not be transmitted.

LSW1

MSB2

MSB1

LSW2

LSWx: Least Significant 16 bits of instruction word

MSBx: Most Significant Byte of instruction word

DSPIC33F Datasheet(PDF) 48 Page - Microchip Technology

DSPIC33F Datasheet(HTML) 48 Page - Microchip Technology

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80

Datasheet Download

Link URL