DSPIC30F2010-30I/SPG Microchip Technology, DSPIC30F2010-30I/SPG Datasheet - Page 48

• Manufacturer Part Number: DSPIC30F2010-30I/SPG
• Description: 16BIT 30MIPS DSPIC, 30F2010, DIP28
• Manufacturer: Microchip Technology
• Series: DsPIC30Fr

Specifications of DSPIC30F2010-30I/SPG

• Core Frequency: 30MHz
• 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
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

dsPIC30F
FIGURE 4-2:
4.4.3
Modulo addressing can be applied to the effective
address (EA) calculation associated with any W regis-
ter. It is important to realize that the address bound-
aries check for addresses less than or greater than the
upper (for incrementing buffers) and lower (for decre-
menting buffers) boundary addresses (not just equal
to). Address changes may, therefore, jump over bound-
aries and still be adjusted correctly (see Section 4.4.4
for restrictions).
DS70082E-page 46
Note:
Byte
Address
0x11D0
0x11FF
MODULO ADDRESSING
APPLICABILITY
The modulo corrected effective address is
written back to the register only when Pre-
Modify or Post-Modify Addressing mode is
used to compute the Effective Address.
When an address offset (e.g., [W7+W2]) is
used, modulo address correction is per-
formed, but the contents of the register
remains unchanged.
Start Addr = 0x11D0
End Addr = 0x11FF
Length = 0x0018 words
DECREMENTING BUFFER MODULO ADDRESSING OPERATION EXAMPLE
MOV
MOV
MOV
MOV
MOV
MOV
MOV
MOV
DO
MOV
AGAIN: DEC
Advance Information
#0x11D0,W0
#0, XMODSRT
0x11FF,W0
W0,XMODEND
#0x8001,W0
W0,MODCON
#0x000F,W0
#0x11E0,W1
AGAIN,#0x17
W0, [W1--]
W0,W0
4.4.4
For an incrementing buffer the circular buffer start
address (lower boundary) is arbitrary, but must be at a
‘zero’ power-of-two boundary (see Section 4.4.1). For
a decrementing buffer, the circular buffer end address
is arbitrary, but must be at a ‘ones’ boundary.
There are no restrictions regarding how much an EA
calculation can exceed the address boundary being
checked and still be successfully corrected.
;set modulo start address
;set modulo end address
;enable W1, X AGU for modulo
;W0 holds buffer fill value
;point W1 to buffer
;fill the 24 buffer locations
;fill the next location
;decrement the fill value
MODULO ADDRESSING
RESTRICTIONS
 2004 Microchip Technology Inc.