BC68F2123 Datasheet, PDF (17/117 Pages) Holtek Semiconductor Inc – Sub-1GHz OOK/FSK TX Soc 1K Flash MCU

BC68F2123
Sub-1GHz OOK/FSK TX Soc 1K Flash MCU
Flash Program Memory
The Program Memory is the location where the user code or program is stored. For the device the
Program Memory is Flash type, which means it can be programmed and re-programmed a large
number of times, allowing the user the convenience of code modification on the same device. By
using the appropriate programming tools, the Flash device offers users the flexibility to conveniently
debug and develop their applications while also offering a means of field programming and
updating.
Structure
The Program Memory has a capacity of 1K×14 bits. The Program Memory is addressed by the
Program Counter and also contains data, table information and interrupt entries. Table data, which
can be setup in any location within the Program Memory, is addressed by a separate table pointer
register.
000H
004H
Reset
Interrupt Vector
01CH
3FFH
14 bits
Program Memory Structure
Special Vectors
Within the Program Memory, certain locations are reserved for the reset and interrupts. The location
000H is reserved for use by the devices reset for program initialisation. After a device reset is
initiated, the program will jump to this location and begin execution.
Look-up Table
Any location within the Program Memory can be defined as a look-up table where programmers can
store fixed data. To use the look-up table, the table pointer must first be setup by placing the address
of the look up data to be retrieved in the table pointer register, TBLP. This register defines the total
address of the look-up table.
After setting up the table pointer, the table data can be retrieved from the Program Memory using
the "TABRDC[m]" or "TABRDL[m]" instructions, respectively. When the instruction is executed,
the lower order table byte from the Program Memory will be transferred to the user defined
Data Memory register [m] as specified in the instruction. The higher order table data byte from
the Program Memory will be transferred to the TBLH special register. Any unused bits in this
transferred higher order byte will be read as "0".
The accompanying diagram illustrates the addressing data flow of the look-up table.
Rev. 1.00
17
January 11, 2017