Flash Program Memory; Structure; Special Vectors; Look-Up Table - Holtek HT67F2350 Manual

Flash Program Memory

The Program Memory is the location where the user code or program is stored. For these devices
series the Program Memory are 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, these Flash devices offer users the flexibility to
conveniently debug and develop their applications while also offering a means of field programming
and updating.

Structure

The Program Memory
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 registers.

Special Vectors

Within the Program Memory, certain locations are reserved for the reset and interrupts. The location
000H is reserved for use by these 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 and TBHP. These registers
define 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 "TABRD [m]" or "TABRDL [m]" instructions respectively when the memory [m] is located in
sector 0. If the memory [m] is located in other sectors except sector 0, the data can be retrieved from
the program memory using the corresponding extended table read instruction such as "LTABRD [m]"
or "LTABRDL [m]" 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. 1.60
Advanced A/D Flash MCU with LCD & EEPROM
Device Capacity
HT67F2350 8K × 16
HT67F2360 16K × 16
HT67F2370 32K × 16
HT67F2390 64K × 16
has a capacity of 8K×16 to 64K×16 bits. The Program Memory is addressed by the
Program Memory
Last Page or
TBHP Register
TBLP Register
Register TBLH
High Byte
54
HT67F2350/HT67F2360
HT67F2370/HT67F2390
Banks
—
0~1
0~3
0~7
Data
16 bits
User Selected
Register
Low Byte
May 16, 2019