DV164136 Microchip Technology, DV164136 Datasheet - Page 92

• Manufacturer Part Number: DV164136
• Description: DEVELOPMENT KIT FOR PIC18
• Manufacturer: Microchip Technology
• Series: PIC®r
• Type: MCUr

Specifications of DV164136

• Contents: Board, Cables, CDs, PICkit™ 3 Programmer, Power Supply
• Processor To Be Evaluated: PIC18F8722, PIC18F87J11
• Interface Type: RS-232, USB
• Operating Supply Voltage: 3.3 V, 5 V
• Silicon Manufacturer: Microchip
• Core Architecture: PIC
• Core Sub-architecture: PIC18
• Silicon Core Number: PIC18F
• Silicon Family Name: PIC18F8xxx
• Kit Contents: PIC18 Exp Brd PICkit 3 Cable CD PSU
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• For Use With/related Products: PIC18F8722, PIC18F87J11
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

PIC18F8722 FAMILY
6.2.2
The Table Latch (TABLAT) is an 8-bit register mapped
into the SFR space. The Table Latch register is used to
hold 8-bit data during data transfers between program
memory and data RAM.
6.2.3
The Table Pointer (TBLPTR) register addresses a byte
within the program memory. The TBLPTR is comprised
of three SFR registers: Table Pointer Upper Byte, Table
Pointer High Byte and Table Pointer Low Byte
(TBLPTRU:TBLPTRH:TBLPTRL). These three regis-
ters join to form a 22-bit wide pointer. The low-order
21 bits allow the device to address up to 2 Mbytes of
program memory space. The 22nd bit allows access to
the device ID, the user ID and the Configuration bits.
The Table Pointer register, TBLPTR, is used by the
TBLRD and TBLWT instructions. These instructions can
update the TBLPTR in one of four ways based on the
table operation. These operations are shown in
Table 6-1. These operations on the TBLPTR only affect
the low-order 21 bits.
TABLE 6-1:
FIGURE 6-3:
DS39646C-page 90
TBLRD*
TBLWT*
TBLRD*+
TBLWT*+
TBLRD*-
TBLWT*-
TBLRD+*
TBLWT+*
Example
21
TABLAT – TABLE LATCH REGISTER
TBLPTR – TABLE POINTER
REGISTER
TABLE POINTER OPERATIONS WITH TBLRD AND TBLWT INSTRUCTIONS
TBLPTRU
TABLE POINTER BOUNDARIES BASED ON OPERATION
16
15
TABLE ERASE/WRITE
TBLPTR<21:6>
TBLPTR is incremented before the read/write
TBLPTR is decremented after the read/write
TABLE READ – TBLPTR<21:0>
TBLPTR is incremented after the read/write
TBLPTRH
Operation on Table Pointer
TBLPTR is not modified
6.2.4
TBLPTR is used in reads, writes and erases of the
Flash program memory.
When a TBLRD is executed, all 22 bits of the TBLPTR
determine which byte is read from program memory
into TABLAT.
When a TBLWT is executed, the six LSbs of the Table
Pointer register (TBLPTR<5:0>) determine which of
the 64 program memory holding registers is written to.
When the timed write to program memory begins (via
the WR bit), the 16 MSbs of the TBLPTR
(TBLPTR<21:6>) determine which program memory
block of 64 bytes is written to. For more detail, see
Section 6.5 “Writing to Flash Program Memory”.
When an erase of program memory is executed, the
16 MSbs of the Table Pointer register (TBLPTR<21:6>)
point to the 64-byte block that will be erased. The Least
Significant bits (TBLPTR<5:0>) are ignored.
Figure 6-3 describes the relevant boundaries of
TBLPTR based on Flash program memory operations.
8
7
TABLE POINTER BOUNDARIES
TBLPTRL
© 2008 Microchip Technology Inc.
TABLE WRITE
TBLPTR<5:0>
0