DSPIC30F2012-20I/SO Microchip Technology, DSPIC30F2012-20I/SO Datasheet - Page 20

• Manufacturer Part Number: DSPIC30F2012-20I/SO
• Description: IC DSPIC MCU/DSP 12K 28SOIC
• Manufacturer: Microchip Technology
• Series: dsPIC™ 30Fr

Specifications of DSPIC30F2012-20I/SO

• Core Processor: dsPIC
• Core Size: 16-Bit
• Speed: 20 MIPS
• Connectivity: I²C, SPI, UART/USART
• Peripherals: Brown-out Detect/Reset, POR, PWM, WDT
• Number Of I /o: 20
• Program Memory Size: 12KB (4K x 24)
• Program Memory Type: FLASH
• Ram Size: 1K x 8
• Voltage - Supply (vcc/vdd): 2.5 V ~ 5.5 V
• Data Converters: A/D 10x12b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 28-SOIC (7.5mm Width)
• Core Frequency: 40MHz
• Embedded Interface Type: I2C, SPI, UART
• No. Of I/o's: 20
• Flash Memory Size: 12KB
• Supply Voltage Range: 2.5V To 5.5V
• Operating Temperature Range: -40°C To +85°C
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• For Use With: XLT28SO-1 - SOCKET TRANSITION 28SOIC 300MIL
• Eeprom Size: -
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant, Lead free / RoHS Compliant
• Other names: DSPIC30F201220ISO

dsPIC30F2011/2012/3012/3013
The core does not support a multi-stage instruction
pipeline. However, a single stage instruction pre-fetch
mechanism is used, which accesses and partially
decodes instructions a cycle ahead of execution, in
order to maximize available execution time. Most
instructions execute in a single cycle with certain
exceptions.
The core features a vectored exception processing
structure for traps and interrupts, with 62 independent
vectors. The exceptions consist of up to 8 traps (of
which 4 are reserved) and 54 interrupts. Each interrupt
is prioritized based on a user assigned priority between
1 and 7 (1 being the lowest priority and 7 being the
highest), in conjunction with a predetermined ‘natural
order’. Traps have fixed priorities ranging from 8 to 15.
2.2
The programmer’s model is shown in Figure 2-1 and
consists of 16 x 16-bit working registers (W0 through
W15), 2 x 40-bit accumulators (AccA and AccB),
STATUS register (SR), Data Table Page register
(TBLPAG), Program Space Visibility Page register
(PSVPAG), DO and REPEAT registers (DOSTART,
DOEND, DCOUNT and RCOUNT) and Program
Counter (PC). The working registers can act as data,
address or offset registers. All registers are memory
mapped. W0 acts as the W register for file register
addressing.
Some of these registers have a shadow register asso-
ciated with each of them, as shown in Figure 2-1. The
shadow register is used as a temporary holding register
and can transfer its contents to or from its host register
upon the occurrence of an event. None of the shadow
registers are accessible directly. The following rules
apply for transfer of registers into and out of shadows.
• PUSH.S and POP.S
• DO instruction
When a byte operation is performed on a working reg-
ister, only the Least Significant Byte of the target regis-
ter is affected. However, a benefit of memory mapped
working registers is that both the Least and Most Sig-
nificant Bytes can be manipulated through byte wide
data memory space accesses.
DS70139C-page 18
W0, W1, W2, W3, SR (DC, N, OV, Z and C bits
only) are transferred.
DOSTART, DOEND, DCOUNT shadows are
pushed on loop start, and popped on loop end.
Programmer’s Model
Preliminary
2.2.1
The dsPIC
the dedicated software Stack Pointer (SP), and will be
automatically modified by exception processing and
subroutine calls and returns. However, W15 can be ref-
erenced by any instruction in the same manner as all
other W registers. This simplifies the reading, writing
and manipulation of the stack pointer (e.g., creating
stack frames).
W15 is initialized to 0x0800 during a Reset. The user
may reprogram the SP during initialization to any
location within data space.
W14 has been dedicated as a stack frame pointer as
defined by the LNK and ULNK instructions. However,
W14 can be referenced by any instruction in the same
manner as all other W registers.
2.2.2
The dsPIC core has a 16-bit STATUS register (SR), the
LS Byte of which is referred to as the SR Low byte
(SRL) and the MS Byte as the SR High byte (SRH).
See Figure 2-1 for SR layout.
SRL contains all the MCU ALU operation status flags
(including the Z bit), as well as the CPU Interrupt Prior-
ity Level status bits, IPL<2:0> and the Repeat Active
status bit, RA. During exception processing, SRL is
concatenated with the MS Byte of the PC to form a
complete word value which is then stacked.
The upper byte of the STATUS register contains the
DSP Adder/Subtracter status bits, the DO Loop Active
bit (DA) and the Digit Carry (DC) status bit.
2.2.3
The program counter is 23-bits wide; bit 0 is always
clear. Therefore, the PC can address up to 4M
instruction words.
Note:
®
SOFTWARE STACK POINTER/
FRAME POINTER
In order to protect against misaligned
stack accesses, W15<0> is always clear.
STATUS REGISTER
PROGRAM COUNTER
devices contain a software stack. W15 is
© 2005 Microchip Technology Inc.