DSPIC30F2011T-20E/ML Microchip Technology, DSPIC30F2011T-20E/ML Datasheet - Page 5

• Manufacturer Part Number: DSPIC30F2011T-20E/ML
• Description: IC DSPIC MCU/DSP 12K 28QFN
• Manufacturer: Microchip Technology
• Series: dsPIC™ 30Fr

Specifications of DSPIC30F2011T-20E/ML

• 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: 12
• 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 8x12b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 125°C
• Package / Case: 28-VQFN Exposed Pad, 28-HVQFN, 28-SQFN, 28-DHVQFN
• For Use With: DAF30-4 - DEVICE ATP FOR ICE4000
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Eeprom Size: -

4. Module: CPU
5. Module: Interrupt Controller
© 2010 Microchip Technology Inc.
When a user executes a DISI #7, for example,
this will disable interrupts for 7 + 1 cycles (7 + the
DISI instruction itself). In this case, the DISI
instruction uses a counter which counts down from
7 to 0. The counter is loaded with 7 at the end of
the DISI instruction.
If the user code executes another DISI on the
instruction cycle where the DISI counter has
become zero, the new DISI count is loaded, but the
DISI state machine does not properly re-engage and
continue to disable interrupts. At this point, all inter-
rupts are enabled. The next time the user code exe-
cutes a DISI instruction, the feature will act normally
and block interrupts.
In summary, it is only when DISI execution is
coincident with the current DISI count = 0, that the
issue occurs. Executing a DISI instruction before
the DISI counter reaches zero will not produce
this error. In this case, the DISI counter is loaded
with the new value and interrupts remain disabled
until the counter becomes zero.
Work around
When executing multiple DISI instructions within
the source code, make sure that subsequent DISI
instructions have at least one instruction cycle
between the time that the DISI counter
decrements to zero and the next DISI instruction.
Alternatively, make sure that subsequent DISI
instructions are called before the DISI counter
decrements to zero.
Affected Silicon Revisions
The following sequence of events will lead to an
address
“Interrupt 1” is used to represent any enabled
dsPIC30F interrupt.
1. User software performs one of the following
2. Interrupt 1 occurs between 2 and 4 instruction
A1
X
operations:
-
-
-
-
cycles after any of the operations listed above.
CPU IPL is raised to Interrupt 1 IPL
level or higher, or
Interrupt 1 IPL is lowered to CPU IPL
level or lower, or
Interrupt 1 is disabled (Interrupt 1 IE
bit set to ‘0’), or
Interrupt 1 flag is cleared
error
trap.
The
generic
term
EXAMPLE 2:
EXAMPLE 3:
.include "p30fxxxx.inc"
...
DISI #4 ; protect the disable
; of INT1
BCLR IEC1, #INT1IE ; disable interrupt 1
... ; next instruction
;protected by DISI
// Note: Macro defined in device include
// files
#define SET_CPU_IPL (ipl){ \
int DISI_save; \
\
DISI_save = DISICNT; \
asm volatile ("disi #0x3FFF");\
SRbits.IPL = ipl; \
__builtin_nop();
__builtin_nop();
DISICNT = DISI_save; } (void) 0;
#include "p30fxxxx.h"
. . .
SET_CPU_IPL (3)
. . .
Work arounds
Work around 1: For Assembly Language
Source Code
The user may disable interrupt nesting, disable
interrupts before modifying the Interrupt 1 set-
ting or execute a DISI instruction before modi-
fying the CPU IPL or Interrupt 1. A minimum
DISI value of 4 is required if the DISI instruction
is executed immediately before the CPU IPL or
Interrupt 1 is modified, as shown in Example 2.
It is necessary to have DISI active for four cycles
after the CPU IPL or Interrupt 1 is modified.
Work around 2: For C Language Source Code
For applications using the C language, MPLAB
C30 versions 1.32 and higher provide several
macros for modifying the CPU IPL. The
SET_CPU_IPL macro provides the ability to
safely modify the CPU IPL, as shown in
Example 3.
There is one level of DISI, so this macro saves
and restores the DISI state. For temporarily
modifying and restoring the CPU IPL, the mac-
ros
RESTORE_CPU_IPL can be used, as shown in
Example 4. These macros also make use of the
SET_CPU_IPL macro.
dsPIC30F2011/2012
SET_AND_SAVE_CPU_IPL
USING DISI
USING SET_CPU_IPL
MACRO
\
\
DS80450D-page 5
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