AN205281
F²MC-8FX Family, MB95200H/210H Series External Interrupts
This application note describes how to set and use the External Interrupt and also describes the function of the
External Interrupts and gives some examples.
Contents
1
2
Introduction ...............................................................1
External Interrupt ......................................................1
2.1
Key Features ...................................................1
2.2
Block Diagram .................................................2
2.3
Connection Diagram ........................................2
2.4
Registers..........................................................3
3
External Interrupt Timing ..........................................4
4
External Interrupt Examples .....................................5
1
4.1
4.2
Basic Functions ............................................... 5
External interrupts and Wake Up from Stop
Mode ................................................................ 7
5
Precautions when Using External Interrupt Circuit ... 9
6
Additional Information ............................................... 9
6.1
Sample Code ................................................. 10
7
Document History ................................................... 15
Introduction
This application note describes how to set and use the External Interrupt.
This application note describes the function of the External Interrupts and gives some examples.
2
External Interrupt
This chapter describes the basic features of the interrupt module
2.1
Key Features
Edge detection circuit
External Interrupt control register
www.cypress.com
Document No. 002-05281 Rev.*A
1
F²MC-8FX Family, MB95200H/210H Series External Interrupts
2.2
Block Diagram
Figure 1 shows the internal block diagram of an External Interrupt channel.
Figure 1. External Interrupts Block Diagram
2.3
Connection Diagram
Figure 2 shows the connection diagram depicting how the External Interrupt pin INTn is interfaced to the external
circuitry.
The pull-up resistor R is connected to limit the current when the key is pressed. The capacitor (hardware debounce)
circuit shown in dotted line is optional, and is used to eliminate the bouncing of the switch. The RC time constant
needs to be chosen according to the bouncing time or debounce delay of the switch. If such arrangement is not used,
then the bouncing needs to be taken care in the software and vice versa.
The INTn needs to be configured to detect a falling edge.
Figure 2. External Interrupt Connection Diagram (Application of switch function)
Please note that this application is only used for switch or keyboard functions.
www.cypress.com
Document No. 002-05281 Rev.*A
2
F²MC-8FX Family, MB95200H/210H Series External Interrupts
2.4
Registers
Please refer to MB95200H/210H Series Hardware Manual Chapter 15 for detailed register setting.
2.4.1
E x t e r n a l I n t e r r u p t C o n t r o l R e g i s t e r ( E I C x y)
The external interrupt control register is used to control interrupt and select the edge polarity for the external interrupt
input and control interrupts.
Table 1. External Interrupt Control Register
2.4.2
bit7
Bit6
Bit5
Bit4
Bit3
Bit2
Bit1
Bit0
Corresponding Ext.
Int. No.
EIC10
EIR1
SL11
SL10
EIE1
EIR0
SL01
SL00
EIE0
INT03
INT02
EIC20
EIR1
SL11
SL10
EIE1
EIR0
SL01
SL00
EIE0
INT05
INT04
EIC30
EIR1
SL11
SL10
EIE1
EIR0
SL01
SL00
EIE0
INT07
INT06
I n t e r r u p t L e ve l S e t t i n g R e g i s t e r s ( I L R 0 t o I L R 5 )
Table 2. Configuration of External Interrupt Level Setting Registers
ILR0
L03
[1:0]
L02
[1:0]
L01
[1:0]
L00
[1:0]
ILR1
L07
[1:0]
L06
[1:0]
L05
[1:0]
L04
[1:0]
ILR2
L11
[1:0]
L10
[1:0]
L09
[1:0]
L08
[1:0]
ILR3
L15
[1:0]
L14
[1:0]
L13
[1:0]
L012
[1:0]
ILR4
L19
[1:0]
L18
[1:0]
L17
[1:0]
L016
[1:0]
ILR5
L23
[1:0]
L22
[1:0]
L21
[1:0]
L020
[1:0]
One of the interrupt level setting registers (ILR0) contains 4 pairs of bits assigned to interrupt requests from an
External Interrupt.
Table 3. Interrupt Source
Interrupt Request No.
Bit Name in Interrupt Level Setting
Register
Interrupt Source
IRQ0
L00[1:0]
External Interrupt ch.4
IRQ1
L01[1:0]
External Interrupt ch.5
IRQ2
L02[1:0]
External Interrupt ch.2/ ch.6
IRQ3
L03[1:0]
External Interrupt ch.3/ ch.7
Each pair of bits (interrupt level setting bits as two-bit data) sets an interrupt level.
Table 4. Relationships between Interrupt Level Setting Bits and Interrupts Levels
LXX[1:0]
Interrupt Level
00
0
01
1
10
2
11
3
Priority
Highest
Lowest (No interrupts accepted)
XX: represents the corresponding interrupt number 00 to 03
During execution of a main program, the interrupt level bits in the condition code register (CCR: IL1, IL0) usually
indicates “11B”.
www.cypress.com
Document No. 002-05281 Rev.*A
3
F²MC-8FX Family, MB95200H/210H Series External Interrupts
3
External Interrupt Timing
This chapter describes timing of external interrupts
The following figure shows events for External Interrupts timing.
After receiving an interrupt, the CPU requires 9 machine clock cycles to perform the following interrupt processing
setup:
Save the program counter (PC) and program status (PS) value
Set the PC to the start address (interrupt vector) of interrupt service routine
Update the interrupt level bits (PS:CCR:IL1,IL0) in the program status (PS) register
Figure 3. Interrupt Processing Time
www.cypress.com
Document No. 002-05281 Rev.*A
4
F²MC-8FX Family, MB95200H/210H Series External Interrupts
4
External Interrupt Examples
This chapter describes examples on external interrupts
4.1
Basic Functions
The following example shows how to set up the External Interrupt Channel 2 and Channel 6 for operation.
Program will enter ISR while generate an Ext Int on channel 2 or channel 6, and clear flag and wait next external
interrupt signal.
/* initial interrupt setting */
void InitExtInt0206 (void)
{
AIDRL |= 0x04;
// disable AN02 input
DDR0 &= 0xBB;
// P02 P06 input
EIC10 = 0x03;
EIC30 = 0x03;
//
//
//
//
External
& Enable
External
& Enable
Interrupt 2 rising
external interrupt
Interrupt 6 rising
external interrupt
edge
output
edge
output
}
/* external ISR */
__interrupt void ExInt0206 (void)
{
if (EIC10_EIR0)
// Ext Int 02 ?
{
EIC10_EIR0 = 0;
// Clear interrupt request flag
...
// interrupt server routine
}
if (EIC30_EIR0)
{
EIC30_EIR0 = 0;
...
// Ext Int 06 ?
// Clear interrupt request flag
// interrupt server routine
}
}
/* main routine */
void main (void)
{
...
InitExtInt0206();
...
}
www.cypress.com
Document No. 002-05281 Rev.*A
5
F²MC-8FX Family, MB95200H/210H Series External Interrupts
Please note that the corresponding interrupt vector and level should be defined in the vector.c module of Cypress’s
standard template project.
...
ILR0 = 0xCF;
//IRQ2: external interrupt ch2 | ch6
...
__interrupt void ExInt0206 (void);
// Prototype
...
#pragma intvect ExInt0206
2
// IRQ2: external interrupt ch2 | ch6
Refer to Appendix Sample Code for project “EI_Basic”.
www.cypress.com
Document No. 002-05281 Rev.*A
6
F²MC-8FX Family, MB95200H/210H Series External Interrupts
4.2
External interrupts and Wake Up from Stop Mode
The following example shows that External Interrupts can be used to request stop mode and wake up the MCU from
this mode.
External Interrupt 2 is used to wake up the MCU while External Interrupt 6 is used to request stop mode.
At the beginning, program will run in normal mode, after an external interrupt (channel 6), set flag from “RUNMODE”
to “STOPREQUEST” in the ISR, then MCU will enter stop mode, and also the external interrupt 2 will wake up the
MCU. Therefore, the MCU mode can switch via external interrupt 2 and 6.
// initialise external interrupt
void InitExtInt0206 (void)
{
AIDRL |= 0x04;
//
DDR0 &= 0xBB;
//
EIC10 = 0x03;
//
//
EIC30 = 0x03;
//
//
}
2 & 6
disable AN02 input
P02 P06 input
External Interrupt 2 rising
& Enable external interrupt
External Interrupt 6 rising
& Enable external interrupt
/* external ISR */
__interrupt void ExInt0206 (void)
{
if (EIC10_EIR0)
{
status = RUNMODE;
EIC10_EIE0 = 0;
EIC10_EIR0 = 0;
EIC10_EIE0 = 1;
}
if (EIC30_EIR0)
{
status = STOPREQUEST;
EIC30_EIE0 = 0;
EIC30_EIR0 = 0;
EIC30_EIE0 = 1;
}
}
edge
output
edge
output
// Ext Int 02 ?
// disable external interrupt 2
// clear interrupt request flag
// enable interrupt request
// Ext Int 06 ?
// disable external interrupt 6
// clear interrupt request flag
// enable interrupt request
/* main routine */
void main (void)
{
...
InitExtInt0206();
...
▼
www.cypress.com
Document No. 002-05281 Rev.*A
7
F²MC-8FX Family, MB95200H/210H Series External Interrupts
▲
status = RUNMODE;
while (1)
{
if (status == STOPREQUEST) // stop mode request
{
PDR0_P00 = 1;
STBC_STP = 1;
}
else
{
// enter stop mode
// run mode
for (i = 0; i < 50000; i ++)
//wait loop
{
__asm(“\tNOP”);
__asm(“\tNOP”);
}
PDR0_P00 = ~PDR0_P00;
// show that MCU is running
}
}
}
Please note that the corresponding interrupt vector and level should be defined in the vector.c module of Cypress’s
standard template project.
/* Interrupt level setting */
void InitIrqLevels (void)
{
...
ILR0 = 0xDF;
...
// IRQ2: external interrupt ch2 | cha6
}
__interrupt void ExInt0206 (void);
// Prototype
...
#pragma intvect ExInt0206
2
// IRQ2: external interrupt ch2 | ch6
...
Refer to Appendix Sample Code for project “EI_ModeSwitch”.
www.cypress.com
Document No. 002-05281 Rev.*A
8
F²MC-8FX Family, MB95200H/210H Series External Interrupts
5
Precautions when Using External Interrupt Circuit
Precautions
6
Set the interrupt request enable bit (EIE) to “0” (disabling interrupt requests) in the process of setting the edge
polarity select bit (SL). Moreover, clear the external interrupt request flag bit (EIR) to “0” after the setting of the
edge polarity.
The operation cannot recover from the interrupt processing routine if the external interrupt request flag bit is “1”
and the interrupt request enable bit is enabled. Always clear the external interrupt request flag bit in the interrupt
processing routine.
Additional Information
For more Information on MB95200 Products, visit the following website:
http://www.cypress.com/8fx-mb95200
www.cypress.com
Document No. 002-05281 Rev.*A
9
F²MC-8FX Family, MB95200H/210H Series External Interrupts
6.1
Sample Code
6.1.1
Project Name: EI_Basic
Basic external ISR
main.c
#include "mb95200.h"
/*--------------------------------------------------------------------------name: InitExtInt0206 ();
function: initial external interrupt
-----------------------------------------------------------------------------*/
void InitExtInt0206 (void)
{
AIDRL |= 0x04;
// disable AN02 input
DDR0 &= 0xBB;
// P02 P06 input
EIC10 = 0x03;
// External Interrupt 2 rising edge
// & Enable interrupt output
EIC30 = 0x03;
// External Interrupt 6 rising edge
// & Enable external interrupt output
}
/*--------------------------------------------------------------------------name: ExInt0206 ();
function: enter while generate an Ext Int
-----------------------------------------------------------------------------*/
__interrupt void ExInt0206 (void)
{
if (EIC10_EIR0)
{
EIC10_EIR0 = 0;
// Clear interrupt request flag
// interrupt server routine
}
if (EIC30_EIR0)
{
EIC30_EIR0 = 0;
// Clear interrupt request flag
// interrupt server routine
}
}
www.cypress.com
Document No. 002-05281 Rev.*A
10
F²MC-8FX Family, MB95200H/210H Series External Interrupts
/*--------------------------------------------------------------------------name: main ();
function: main loop
-----------------------------------------------------------------------------*/
void main(void)
{
InitExtInt0206();
InitIrqLevels();
__EI();
while(1);
}
vector.c
#include "mb95200.h"
/*--------------------------------------------------------------------------name: InitIrqLevels ();
function: Interrupt level (priority) setting
-----------------------------------------------------------------------------*/
void InitIrqLevels(void)
{
ILR0 = 0xCF;
// IRQ0:
external interrupt ch4
// IRQ1:
external interrupt ch5
// IRQ2:
external interrupt ch2 | ch6
// IRQ3:
external interrupt ch3 | ch7
}
/*--------------------------------------------------------------------------Prototypes
-----------------------------------------------------------------------------*/
__interrupt void ExInt0206 (void);
/*--------------------------------------------------------------------------Vector definition
-----------------------------------------------------------------------------*/
#pragma intvect ExInt0206
www.cypress.com
2
// IRQ2:
external interrupt ch2 | ch6
Document No. 002-05281 Rev.*A
11
F²MC-8FX Family, MB95200H/210H Series External Interrupts
6.1.2
Project Name: EI_ModeSwitch
The MCU wakes up from stop mode via an external interrupt
main.c
#include "mb95200.h"
#define RUNMODE
1
#define STOPREQUEST
0
unsigned char status;
/*--------------------------------------------------------------------------name: InitExtInt0206 ();
function: initial external interrupt
-----------------------------------------------------------------------------*/
void InitExtInt0206 (void)
{
AIDRL |= 0x04;
// disable AN02 input
DDR0 &= 0xBB;
// P02 P06 input
EIC10 = 0x03;
// External Interrupt 2 rising edge
// & Enable interrupt output
EIC30 = 0x03;
// External Interrupt 6 rising edge
// & Enable external interrupt output
}
/*--------------------------------------------------------------------------name: ExInt0206 ();
function: mode switch
-----------------------------------------------------------------------------*/
__interrupt void ExInt0206 (void)
{
if (EIC10_EIR0)
{
status = RUNMODE;
EIC10_EIE0 = 0;
// disable external interrupt 2
EIC10_EIR0 = 0;
// clear interrupt request flag
EIC10_EIE0 = 1;
// enable interrupt request
}
if (EIC30_EIR0)
{
status = STOPREQUEST;
www.cypress.com
Document No. 002-05281 Rev.*A
12
F²MC-8FX Family, MB95200H/210H Series External Interrupts
EIC30_EIE0 = 0;
// disable external interrupt 6
EIC30_EIR0 = 0;
// clear interrupt request flag
EIC30_EIE0 = 1;
// enable interrupt request
}
}
/*--------------------------------------------------------------------------name: main ();
function: main loop
-----------------------------------------------------------------------------*/
void main (void)
{
unsigned int i;
InitExtInt0206();
DDR0_P05 = 1;
InitIrqLevels();
__EI();
status = RUNMODE;
while (1)
{
if (status == STOPREQUEST) // stop mode request
{
PDR0_P00 = 1;
STBC_STP = 1;
// go to stop mode
}
else
// run mode
{
for (i = 0; i < 5000; i ++)
//wait loop
{
__asm("\tNOP");
__asm("\tNOP");
}
PDR0_P05 = ~PDR0_P05;
// show, that MCU is running
}
}
}
www.cypress.com
Document No. 002-05281 Rev.*A
13
F²MC-8FX Family, MB95200H/210H Series External Interrupts
vector.c
#include "mb95200.h"
/*--------------------------------------------------------------------------name: InitIrqLevels ();
function: Interrupt level (priority) setting
-----------------------------------------------------------------------------*/
void InitIrqLevels(void)
{
ILR0 = 0xCF;
// IRQ0:
external interrupt ch4
// IRQ1:
external interrupt ch5
// IRQ2:
external interrupt ch2 | ch6
// IRQ3:
external interrupt ch3 | ch7
}
/*--------------------------------------------------------------------------Prototypes
-----------------------------------------------------------------------------*/
__interrupt void ExInt0206 (void);
/*--------------------------------------------------------------------------Vector definition
-----------------------------------------------------------------------------*/
#pragma intvect ExInt0206
www.cypress.com
2
// IRQ2:
external interrupt ch2 | ch6
Document No. 002-05281 Rev.*A
14
F²MC-8FX Family, MB95200H/210H Series External Interrupts
7
Document History
Document Title: AN205281 - F²MC-8FX Family, MB95200H/210H Series External Interrupts
Document Number: 002-05281
Revision
**
ECN
-
Orig. of
Change
HUAL
Submission
Date
Description of Change
03/20/2008
Initial release
07/18/2008
Added URL in chapter 6 Additional Information; modified
Some sample code.
*A
www.cypress.com
5264352
HUAL
06/03/2016
Migrated Spansion Application Note MCU-AN-500007-E-11 to Cypress
format
Document No. 002-05281 Rev.*A
15
F²MC-8FX Family, MB95200H/210H Series External Interrupts
Worldwide Sales and Design Support
Cypress maintains a worldwide network of offices, solution centers, manufacturer’s representatives, and distributors. To find
the office closest to you, visit us at Cypress Locations.
PSoC® Solutions
Products
®
®
ARM Cortex Microcontrollers
cypress.com/arm
PSoC 1 | PSoC 3 | PSoC 4 | PSoC 5LP
Automotive
cypress.com/automotive
Cypress Developer Community
Clocks & Buffers
cypress.com/clocks
Interface
cypress.com/interface
Lighting & Power Control
cypress.com/powerpsoc
Memory
cypress.com/memory
PSoC
cypress.com/psoc
Touch Sensing
cypress.com/touch
USB Controllers
cypress.com/usb
Wireless/RF
cypress.com/wireless
Forums | Projects | Videos | Blogs | Training| Components
Technical Support
cypress.com/support
PSoC is a registered trademark and PSoC Creator is a trademark of Cypress Semiconductor Corporation. All other trademarks or registered trademarks
referenced herein are the property of their respective owners.
Cypress Semiconductor
198 Champion Court
San Jose, CA 95134-1709
Phone
Fax
Website
: 408-943-2600
: 408-943-4730
: www.cypress.com
© Cypress Semiconductor Corporation, 2008-2016. This document is the property of Cypress Semiconductor Corporation and its subsidiaries, including
Spansion LLC (“Cypress”). This document, including any software or firmware included or referenced in this document (“Software”), is owned by
Cypress under the intellectual property laws and treaties of the United States and other countries worldwide. Cypress reserves all rights under such
laws and treaties and does not, except as specifically stated in this paragraph, grant any license under its patents, copyrights, trademarks, or other
intellectual property rights. If the Software is not accompanied by a license agreement and you do not otherwise have a written agreement with
Cypress governing the use of the Software, then Cypress hereby grants you a personal, non-exclusive, nontransferable license (without the right to
sublicense) (1) under its copyright rights in the Software (a) for Software provided in source code form, to modify and reproduce the Software solely for
use with Cypress hardware products, only internally within your organization, and (b) to distribute the Software in binary code form externally to end
users (either directly or indirectly through resellers and distributors), solely for use on Cypress hardware product units, and (2) under those claims of
Cypress’s patents that are infringed by the Software (as provided by Cypress, unmodified) to make, use, distribute, and import the Software solely for
use with Cypress hardware products. Any other use, reproduction, modification, translation, or compilation of the Software is prohibited.
TO THE EXTENT PERMITTED BY APPLICABLE LAW, CYPRESS MAKES NO WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, WITH REGARD
TO THIS DOCUMENT OR ANY SOFTWARE OR ACCOMPANYING HARDWARE, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. To the extent permitted by applicable law, Cypress reserves the right to
make changes to this document without further notice. Cypress does not assume any liability arising out of the application or use of any product or
circuit described in this document. Any information provided in this document, including any sample design information or programming code, is
provided only for reference purposes. It is the responsibility of the user of this document to properly design, program, and test the functionality and
safety of any application made of this information and any resulting product. Cypress products are not designed, intended, or authorized for use as
critical components in systems designed or intended for the operation of weapons, weapons systems, nuclear installations, life-support devices or
systems, other medical devices or systems (including resuscitation equipment and surgical implants), pollution control or hazardous substances
management, or other uses where the failure of the device or system could cause personal injury, death, or property damage (“Unintended Uses”). A
critical component is any component of a device or system whose failure to perform can be reasonably expected to cause the failure of the device or
system, or to affect its safety or effectiveness. Cypress is not liable, in whole or in part, and you shall and hereby do release Cypress from any claim,
damage, or other liability arising from or related to all Unintended Uses of Cypress products. You shall indemnify and hold Cypress harmless from and
against all claims, costs, damages, and other liabilities, including claims for personal injury or death, arising from or related to any Unintended Uses of
Cypress products.
Cypress, the Cypress logo, Spansion, the Spansion logo, and combinations thereof, PSoC, CapSense, EZ-USB, F-RAM, and Traveo are trademarks or
registered trademarks of Cypress in the United States and other countries. For a more complete list of Cypress trademarks, visit cypress.com. Other
names and brands may be claimed as property of their respective owners.
www.cypress.com
Document No. 002-05281 Rev.*A
16