ST72F321AR9TA STMicroelectronics, ST72F321AR9TA Datasheet - Page 21

• Manufacturer Part Number: ST72F321AR9TA
• Description: IC MCU 8BIT 60KB FLASH 64-TQFP
• Manufacturer: STMicroelectronics
• Series: ST7r

Specifications of ST72F321AR9TA

• Core Processor: ST7
• Core Size: 8-Bit
• Speed: 8MHz
• Connectivity: I²C, SCI, SPI
• Peripherals: LVD, POR, PWM, WDT
• Number Of I /o: 48
• Program Memory Size: 60KB (60K x 8)
• Program Memory Type: FLASH
• Ram Size: 2K x 8
• Voltage - Supply (vcc/vdd): 3.8 V ~ 5.5 V
• Data Converters: A/D 16x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 64-TQFP, 64-VQFP
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Eeprom Size: -

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
■
■
■
■
■
■
■
■
Figure 8. CPU Registers
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
RESET VALUE = STACK HIGHER ADDRESS
RESET VALUE = RESET VECTOR @ FFFEh-FFFFh
15
15
RESET VALUE = 1
PCH
8 7
8
RESET VALUE = XXh
RESET VALUE = XXh
RESET VALUE = XXh
7
7
7
1
7
7
1 1 X 1 X X
1 I1 H I0 N Z
PCL
0
0
0
0
X
0
C
0
X INDEX REGISTER
Y INDEX REGISTER
5.3 CPU REGISTERS
The six CPU registers shown in
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
PROGRAM COUNTER
CONDITION CODE REGISTER
STACK POINTER
ST72321Rx ST72321ARx ST72321Jx
X = Undefined Value
Figure 1
are not
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