HT48C10 View Datasheet(PDF) - Holtek Semiconductor
Part Name
Description
MFG CO.
'HT48C10' PDF : 59 Pages View PDF
HT48CXX/HT48RXX
Program memory – ROM
The program memory (ROM) is used to store the
program instructions that are to be executed. It
contains data, table, and interrupt entries, and
is organized into 1024×14 bits, 2048×14 bits,
4096×15 bits, or 8192×16 bits according to the mi-
crocontroller (HT48C10/ HT48C30/HT48C50/
HT48C70) selected. These bits are all addressed by the
PC and table pointer.
Certain locations in the ROM stated below are
reserved for special usage in the four microcon-
trollers except location 00CH which is used for
the HT48C50/HT48C70 exclusively.
• Location 000H
Location 000H is reserved for program in-
itialization. After chip reset, the program al-
ways begins execution at this area.
• Location 004H
Location 004H is reserved for external inter-
rupt service program. If the INT input pin is
activated, the interrupt is enabled, and the
stack is not full, the program begins execution
at location 004H.
• Location 008H
Location 008H is reserved for the timer/event
counter interrupt service program of the
HT48C10/HT48C30 and for the timer/event
counter 0 interrupt service program of the
Program memory
HT48C50/HT48C70. If the timer interrupt re-
sults from a timer/event counter overflow of
the HT48C10/HT48C30 or a timer/event
counter 0 overflow of the HT48C50/HT48C70,
and the interrupt is enabled, and the stack is
not full, the program begins execution at loca-
tion 008H.
Mode
Initial reset
External interrupt
Timer/event counter 0 overflow
Timer/event counter 1 overflow
Skip
Loading PCL
Jump, call branch
Return from subroutine
Contents of Program Counter (m bits)
0000H
0004H
0008H
000CH
PC+2
Low byte replaced by instruction code
Instruction code
Stack register
Notes: m=10 for the HT48C10
m=11 for the HT48C30
m=12 for the HT48C50
m=13 for the HT48C70
14
25th May ’99
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