参数资料
| 型号： | AT80C51RA2-RLTUL |
| 厂商： | Atmel |
| 文件页数： | 24/84页 |
| 文件大小： | 0K |
| 描述： | IC 8051 MCU ROMLESS 44VQFP |
| 标准包装： | 800 |
| 系列： | 80C |
| 核心处理器： | 8051 |
| 芯体尺寸： | 8-位 |
| 速度： | 30/20MHz |
| 连通性： | UART/USART |
| 外围设备： | POR，PWM，WDT |
| 输入/输出数： | 32 |
| 程序存储器类型： | ROMless |
| RAM 容量： | 512 x 8 |
| 电压 - 电源 (Vcc/Vdd)： | 2.7 V ~ 5.5 V |
| 振荡器型： | 内部 |
| 工作温度： | -40°C ~ 85°C |
| 封装/外壳： | 44-LQFP |
| 包装： | 托盘 |
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dsPIC33FJ32GP302/304, dsPIC33FJ64GPX02/X04, AND dsPIC33FJ128GPX02/X04
DS70292G-page 32
2007-2012 Microchip Technology Inc.
3.8.1
MULTIPLIER
The 17-bit x 17-bit multiplier is capable of signed or
unsigned operation and can multiplex its output using a
scaler to support either 1.31 fractional (Q31) or 32-bit
integer results. Unsigned operands are zero-extended
into the 17th bit of the multiplier input value. Signed
operands are sign-extended into the 17th bit of the
multiplier input value. The output of the 17-bit x 17-bit
multiplier/scaler is a 33-bit value that is sign-extended
to 40 bits. Integer data is inherently represented as a
signed two’s complement value, where the Most
Significant bit (MSb) is defined as a sign bit. The range
of an N-bit two’s complement integer is -2N-1 to 2N-1 – 1.
For a 16-bit integer, the data range is -32768
(0x8000) to 32767 (0x7FFF) including 0.
For a 32-bit integer, the data range is -
2,147,483,648 (0x8000 0000) to 2,147,483,647
(0x7FFF FFFF).
When the multiplier is configured for fractional
multiplication, the data is represented as a two’s
complement fraction, where the MSb is defined as a
sign bit and the radix point is implied to lie just after the
sign bit (QX format). The range of an N-bit two’s
complement fraction with this implied radix point is -1.0
to (1 – 21-N). For a 16-bit fraction, the Q15 data range
is -1.0 (0x8000) to 0.999969482 (0x7FFF) including 0
and has a precision of 3.01518x10-5. In Fractional
mode, the 16 x 16 multiply operation generates a 1.31
product that has a precision of 4.65661 x 10-10.
The same multiplier is used to support the MCU
multiply instructions, which include integer 16-bit
signed, unsigned and mixed sign multiply operations.
The MUL instruction can be directed to use byte or
word-sized operands. Byte operands direct a 16-bit
result, and word operands direct a 32-bit result to the
specified registers in the W array.
3.8.2
DATA ACCUMULATORS AND
ADDER/SUBTRACTER
The data accumulator consists of a 40-bit adder/
subtracter with automatic sign extension logic. It can
select one of two accumulators (A or B) as its pre-
accumulation
source
and
post-accumulation
destination. For the ADD and LAC instructions, the data
to be accumulated or loaded can be optionally scaled
using the barrel shifter prior to accumulation.
3.8.2.1
Adder/Subtracter, Overflow and
Saturation
The adder/subtracter is a 40-bit adder with an optional
zero input into one side, and either true or complement
data into the other input.
In the case of addition, the Carry/Borrow input is
active-high and the other input is true data (not
complemented).
In the case of subtraction, the Carry/Borrow input
is active-low and the other input is complemented.
The adder/subtracter generates Overflow Status bits,
SA/SB and OA/OB, which are latched and reflected in
the STATUS register:
Overflow from bit 39: this is a catastrophic
overflow in which the sign of the accumulator is
destroyed.
Overflow into guard bits 32 through 39: this is a
recoverable overflow. This bit is set whenever all
the guard bits are not identical to each other.
The adder has an additional saturation block that
controls accumulator data saturation, if selected. It
uses the result of the adder, the Overflow Status bits
described
previously
and
the
SAT<A:B>
(CORCON<7:6>) and ACCSAT (CORCON<4>) mode
control bits to determine when and to what value to
saturate.
Six STATUS register bits support saturation and
overflow:
OA: ACCA overflowed into guard bits
OB: ACCB overflowed into guard bits
SA: ACCA saturated (bit 31 overflow and
saturation)
or
ACCA overflowed into guard bits and saturated
(bit 39 overflow and saturation)
SB: ACCB saturated (bit 31 overflow and
saturation)
or
ACCB overflowed into guard bits and saturated
(bit 39 overflow and saturation)
OAB: Logical OR of OA and OB
SAB: Logical OR of SA and SB
The OA and OB bits are modified each time data
passes through the adder/subtracter. When set, they
indicate that the most recent operation has overflowed
into the accumulator guard bits (bits 32 through 39).
The OA and OB bits can also optionally generate an
arithmetic
warning
trap
when
set
and
the
corresponding Overflow Trap Flag Enable bits (OVATE,
OVBTE) in the INTCON1 register are set (refer to
Section 7.0 “Interrupt Controller”). This allows the
user application to take immediate action, for example,
to correct the system gain.
The SA and SB bits are modified each time data
passes through the adder/subtracter, but can only be
cleared by the user application. When set, they indicate
that the accumulator has overflowed its maximum
range (bit 31 for 32-bit saturation or bit 39 for 40-bit sat-
uration) and is saturated (if saturation is enabled).
When saturation is not enabled, SA and SB default to
bit 39 overflow and thus indicate that a catastrophic
overflow has occurred. If the COVTE bit in the
INTCON1 register is set, the SA and SB bits generate
an arithmetic warning trap when saturation is disabled.
相关PDF资料 |
PDF描述 |
|---|---|
| AT80C51RA2-3CSUM | IC 8051 MCU ROMLESS 40DIP |
| AT80C51RA2-3CSUL | IC 8051 MCU ROMLESS 40DIP |
| AT80C31X2-SLSUM | IC 8031 MCU ROMLESS 44PLCC |
| AT80C31X2-SLSUL | IC 8031 MCU ROMLESS 44PLCC |
| 213300-2 | CONN JACKSCREW PLUG 34 POS |
相关代理商/技术参数 |
参数描述 |
|---|---|
| AT80C51RA2-RLTUM | 功能描述:8位微控制器 -MCU RLESS RA 40MHZ 5V COM TEMP RoHS:否 制造商:Silicon Labs 核心:8051 处理器系列:C8051F39x 数据总线宽度:8 bit 最大时钟频率:50 MHz 程序存储器大小:16 KB 数据 RAM 大小:1 KB 片上 ADC:Yes 工作电源电压:1.8 V to 3.6 V 工作温度范围:- 40 C to + 105 C 封装 / 箱体:QFN-20 安装风格:SMD/SMT |
| AT80C51RA2-SLRUL | 功能描述:8位微控制器 -MCU MICRO RLESS RA 40MHZ 3V COM TEMP RoHS:否 制造商:Silicon Labs 核心:8051 处理器系列:C8051F39x 数据总线宽度:8 bit 最大时钟频率:50 MHz 程序存储器大小:16 KB 数据 RAM 大小:1 KB 片上 ADC:Yes 工作电源电压:1.8 V to 3.6 V 工作温度范围:- 40 C to + 105 C 封装 / 箱体:QFN-20 安装风格:SMD/SMT |
| AT80C51RA2-SLRUM | 功能描述:8位微控制器 -MCU RLESS RA 40MHZ 5V RoHS:否 制造商:Silicon Labs 核心:8051 处理器系列:C8051F39x 数据总线宽度:8 bit 最大时钟频率:50 MHz 程序存储器大小:16 KB 数据 RAM 大小:1 KB 片上 ADC:Yes 工作电源电压:1.8 V to 3.6 V 工作温度范围:- 40 C to + 105 C 封装 / 箱体:QFN-20 安装风格:SMD/SMT |
| AT80C51RA2-SLSCL | 制造商:IRF 制造商全称:International Rectifier 功能描述:High Performance 8-bit Microcontroller |
| AT80C51RA2-SLSCV | 制造商:IRF 制造商全称:International Rectifier 功能描述:High Performance 8-bit Microcontroller |
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