ST92F250V9TC View Datasheet(PDF) - STMicroelectronics

Part Name

Description

Manufacturer

ST92F250V9TC

8/16-BIT SINGLE VOLTAGE FLASH MCU FAMILY WITH RAM, E³ ™ (EMULATED EEPROM), CAN 2.0B AND J1850 BLPD

STMicroelectronics 

ST92F124/F150/F250 - INTERRUPTS

WAKE-UP / INTERRUPT LINES MANAGEMENT UNIT (Cont’d)

5.12.3 Functional Description

5.12.3.1 Interrupt Mode

To configure the 16 wake-up lines as interrupt

sources, use the following procedure:

1. Configure the mask bits of the 16 wake-up lines

(WUMRL, WUMRH)

2. Configure the triggering edge registers of the

wake-up lines (WUTRL, WUTRH)

3. Set bit 7 of EIMR (R244 Page 0) and EITR

(R242 Page 0) registers of the CPU: so an

interrupt coming from one of the 16 lines can be

correctly acknowledged

4. Reset the WKUP-INT bit in the WUCTRL regis-

ter to disable Wake-up Mode

5. Set the ID1S bit in the WUCTRL register to

enable the 16 wake-up lines as external inter-

rupt source lines.

5.12.3.2 Wake-up Mode Selection

To configure the 16 lines as wake-up sources, use

the following procedure:

1. Configure the mask bits of the 16 wake-up lines

(WUMRL, WUMRH).

2. Configure the triggering edge registers of the

wake-up lines (WUTRL, WUTRH).

3. Set, as for Interrupt Mode selection, bit 7 of

EIMR and EITR registers only if an interrupt

routine is to be executed after a wake-up event.

Otherwise, if the wake-up event only restarts

the execution of the code from where it was

stopped, the INTD1 interrupt channel must be

masked.

wake-up event does not require an interrupt

response.

7. Write the sequence 1,0,1 to the STOP bit of the

WUCTRL register with three consecutive write

operations. This is the STOP bit setting

sequence.

To detect if STOP Mode was entered or not, im-

mediately after the STOP bit setting sequence,

poll the RCCU EX_STP bit (R242.7, Page 55) and

the STOP bit itself.

5.12.3.3 STOP Mode Entry Conditions

Assuming the ST9 is in Run mode: during the

STOP bit setting sequence the following cases

may occur:

Case 1: NMI = 0, wrong STOP bit setting se-

quence

This can happen if an Interrupt/DMA request is ac-

knowledged during the STOP bit setting se-

quence. In this case polling the STOP and

EX_STP bits will give:

STOP = 0, EX_STP = 0

This means that the ST9 did not enter STOP mode

due to a bad STOP bit setting sequence: the user

must retry the sequence.

Case 2: NMI = 0, correct STOP bit setting se-

quence

In this case the ST9 enters STOP mode. There are

two ways to exit STOP mode:

1. A wake-up interrupt (not an NMI interrupt) is

acknowledged. That implies:

STOP = 0, EX_STP = 1

4. Since the RCCU can generate an interrupt

request when exiting from STOP mode, take

care to mask it even if the wake-up event is

only to restart code execution.

5. Set the WKUP-INT bit in the WUCTRL register

to select Wake-up Mode

6. Set the ID1S bit in the WUCTRL register to

enable the 16 wake-up lines as external inter-

rupt source lines. This is not mandatory if the

This means that the ST9 entered and exited STOP

mode due to an external wake-up line event.

2. A NMI rising edge woke up the ST9. This

implies:

STOP = 1, EX_STP = 1

This means that the ST9 entered and exited STOP

mode due to an NMI (rising edge) event. The user

should clear the STOP bit via software.

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