dsPIC33F/PIC24H PROGRAMMING SPECIFICATION
4.2.6
15
READCCOMMAND
4.2.7
15
READPCOMMAND
12 11
8 7
0
12 11
8 7
0
Opcode
Length
Addr_MSB
Opcode
Length
Addr_MSB
N
N
Addr_LS
Reserved
Addr_LS
Field
Description
Field
Description
Opcode
Length
N
0x1
0x3
Opcode
Length
N
0x2
0x4
Number of 8-bit Configuration registers
or Device ID registers to read (max of
256)
Number of 24-bit instructions to read
(max of 32768)
Addr_MSB MSB of 24-bit source address
Reserved
Addr_MSB
Addr_LS
0x0
Addr_LS
Least Significant 16 bits of 24-bit
source address
MSB of 24-bit source address
Least Significant 16 bits of 24-bit
source address
The READCcommand instructs the programming exec-
utive to read N Configuration registers or Device ID
registers, starting from the 24-bit address specified by
Addr_MSB and Addr_LS. This command can only be
used to read 8-bit or 16-bit data.
The READPcommand instructs the programming exec-
utive to read N 24-bit words of code memory, starting
from the 24-bit address specified by Addr_MSB and
Addr_LS. This command can only be used to read 24-
bit data. All data returned in the response to this com-
mand uses the packed data format described in
Section 4.2.2 “Packed Data Format”.
When this command is used to read Configuration
registers, the upper byte in every data word returned by
the programming executive is 0x00 and the lower byte
contains the Configuration register value.
Expected Response (2 + 3 * N/2 words for N even):
0x1200
2 + 3 * N/2
Expected Response (4 + 3 * (N – 1)/2 words
for N odd):
0x1100
Least significant program memory word 1
2 + N
...
Configuration register or Device ID Register 1
Least significant data word N
...
Expected Response (4 + 3 * (N – 1)/2 words
for N odd):
Configuration register or Device ID Register N
0x1200
4 + 3 * (N – 1)/2
Least significant program memory word 1
...
Note:
Reading unimplemented memory will
cause the programming executive to
reset. Please ensure that only memory
locations present on a particular device
are accessed.
MSB of program memory word N (zero padded)
Note:
Reading unimplemented memory will
cause the programming executive to
reset. Please ensure that only memory
locations present on a particular device
are accessed.
DS70152D-page 50
Preliminary
© 2007 Microchip Technology Inc.
MICROCHIP [ MICROCHIP ]
