ST7MC2N6T3 View Datasheet(PDF) - STMicroelectronics
Part Name
Description
Manufacturer
ST7MC2N6T3
STMicroelectronics
ST7MC2N6T3 Datasheet PDF : 309 Pages
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ST7MC1xx/ST7MC2xx
5 CENTRAL PROCESSING UNIT
5.1 INTRODUCTION
This CPU has a full 8-bit architecture and contains
six internal registers allowing efficient 8-bit data
manipulation.
5.2 MAIN FEATURES
■ Enable executing 63 basic instructions
■ Fast 8-bit by 8-bit multiply
■ 17 main addressing modes (with indirect
addressing mode)
■ Two 8-bit index registers
■ 16-bit stack pointer
■ Low power Halt and Wait modes
■ Priority maskable hardware interrupts
■ Non-maskable software/hardware interrupts
Figure 11. CPU Registers
7
0
RESET VALUE = XXh
7
0
RESET VALUE = XXh
7
0
RESET VALUE = XXh
15
PCH
87
PCL
0
RESET VALUE = RESET VECTOR @ FFFEh-FFFFh
7
0
1 1 I1 H I0 N Z C
RESET VALUE = 1 1 1 X 1 X X X
15
87
0
RESET VALUE = STACK HIGHER ADDRESS
5.3 CPU REGISTERS
The six CPU registers shown in Figure 11 are not
present in the memory mapping and are accessed
by specific instructions.
Accumulator (A)
The Accumulator is an 8-bit general purpose reg-
ister used to hold operands and the results of the
arithmetic and logic calculations and to manipulate
data.
Index Registers (X and Y)
These 8-bit registers are used to create effective
addresses or as temporary storage areas for data
manipulation. (The Cross-Assembler generates a
precede instruction (PRE) to indicate that the fol-
lowing instruction refers to the Y register.)
The Y register is not affected by the interrupt auto-
matic procedures.
Program Counter (PC)
The program counter is a 16-bit register containing
the address of the next instruction to be executed
by the CPU. It is made of two 8-bit registers PCL
(Program Counter Low which is the LSB) and PCH
(Program Counter High which is the MSB).
ACCUMULATOR
X INDEX REGISTER
Y INDEX REGISTER
PROGRAM COUNTER
CONDITION CODE REGISTER
STACK POINTER
X = Undefined Value
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