Holtek HT46R22, Handbook

Page: 28 / 162

Program Memory
The Program Memory is the location where the user code or program is stored. For
microcontrollers, two types of Program Memory are usually supplied. The first type is the One-
Time Programmable (OTP) Memory where users can program their application code into the de-
vice. Devices with OTP memory are denoted by having an
²
R
²
within their device name. By using
the appropriate programming tools, OTP devices offer users the flexibility to freely develop their
applications which may be useful during debug or for products requiring frequent upgrades or pro-
gram changes. OTP devices are also applicable for use in applications that require low or medium
volume production runs. The other type of memory is the mask ROM memory, denoted by having
a
²
C
²
within the device name. These devices offer the most cost effective solutions for high volume
products.
Organization
The Program Memory has a capacity of 2K by 14 to 8K by 16 bits depending upon which device is
selected. The Program Memory is addressed by the Program Counter and also contains data, ta-
ble information and interrupt entries. Table data, which can be setup in any location within the Pro-
gram Memory, is addressed by separate table pointer registers.
The following diagram shows the Program Memory for the A/D Type microcontroller series.
Chapter 1 Hardware Structure
19
N o t I m p l e m e n t e d
1 6 b i t s 1 5 b i t s
1 4 b i t s 1 4 b i t s
3 F F H
4 0 0 H
7 F F H
8 0 0 H
F F F H
1 0 0 0 H
1 F F F H
0 1 4 H
I
2
C B u s
I n t e r r u p t V e c t o r
I
2
C B u s
I n t e r r u p t V e c t o r
I
2
C B u s
I n t e r r u p t V e c t o r
A / D C o n v e r t e r
I n t e r r u p t V e c t o r
I n i t i a l i z a t i o n
V e c t o r
E x t e r n a l
I n t e r r u p t V e c t o r
T i m e r / C o u n t e r 0
I n t e r r u p t V e c t o r
I n i t i a l i z a t i o n
V e c t o r
E x t e r n a l
I n t e r r u p t V e c t o r
I n i t i a l i z a t i o n
V e c t o r
E x t e r n a l
I n t e r r u p t V e c t o r
T i m e r / C o u n t e r
I n t e r r u p t V e c t o r
I n i t i a l i z a t i o n
V e c t o r
E x t e r n a l
I n t e r r u p t V e c t o r
T i m e r / C o u n t e r
I n t e r r u p t V e c t o r
H T 4 6 R 2 3
H T 4 6 C 2 3
H T 4 6 R 2 4
H T 4 6 C 2 4
H T 4 6 R 4 7
H T 4 6 C 4 7
H T 4 6 R 2 2
H T 4 6 C 2 2
T i m e r / C o u n t e r 1
I n t e r r u p t V e c t o r
A / D C o n v e r t e r
I n t e r r u p t V e c t o r
A / D C o n v e r t e r
I n t e r r u p t V e c t o r
A / D C o n v e r t e r
I n t e r r u p t V e c t o r
T i m e r / C o u n t e r
I n t e r r u p t V e c t o r
0 0 0 H
0 0 4 H
0 0 8 H
0 0 C H
0 1 0 H