ST92124V1Q-Auto STMicroelectronics, ST92124V1Q-Auto Datasheet - Page 104

• Manufacturer Part Number: ST92124V1Q-Auto
• Description: 8-bit MCU for automotive
• Manufacturer: STMicroelectronics

Specifications of ST92124V1Q-Auto

• Internal Memory: Single Voltage FLASH up to 256 Kbytes, RAM up to 8Kbytes, 1K byte E3 TM (Emulated EEPROM)
• Minimum Instruction Time: 83 ns (24 MHz int. clock)

ST92124xxx-Auto/150xxxxx-Auto/250xxxx-Auto
5.7.2 IMPORTANT NOTE ON STANDARD
INTERRUPTS
Refer to
5.8 TOP LEVEL INTERRUPT
The Top Level Interrupt channel can be assigned
either to the external pin NMI or to the Timer/
Watchdog according to the status of the control bit
EIVR.TLIS (R246.2, Page 0). If this bit is high (the
reset condition) the source is the external pin NMI.
If it is low, the source is the Timer/ Watchdog End
Of Count. When the source is the NMI external
pin, the control bit EIVR.TLTEV (R246.3; Page 0)
selects between the rising (if set) or falling (if reset)
edge generating the interrupt request. When the
selected event occurs, the CICR.TLIP bit (R230.6)
is set. Depending on the mask situation, a Top
Level Interrupt request may be generated. Two
kinds of masks are available, a Maskable mask
and a Non-Maskable mask. The first mask is the
CICR.TLI bit (R230.5): it can be set or cleared to
enable or disable respectively the Top Level Inter-
rupt request. If it is enabled, the global Enable In-
terrupt bit, CICR.IEN (R230.4) must also be ena-
bled in order to allow a Top Level Request.
The second mask NICR.TLNM (R247.7) is a set-
only mask. Once set, it enables the Top Level In-
terrupt request independently of the value of
CICR.IEN and it cannot be cleared by the pro-
gram. Only the processor RESET cycle can clear
this bit. This does not prevent the user from ignor-
ing some sources due to a change in TLIS.
The Top Level Interrupt Service Routine cannot be
interrupted by any other interrupt or DMA request,
in any arbitration mode, not even by a subsequent
Top Level Interrupt request.
104/430
9
Section 13.4 on page
414.
Warning. The interrupt machine cycle of the Top
Level Interrupt does not clear the CICR.IEN bit,
and the corresponding iret does not set it. Fur-
thermore the TLI never modifies the CPL bits and
the NICR register.
5.9
INTERRUPTS
Some of the on-chip peripherals have their own
specific interrupt unit containing one or more inter-
rupt channels, or DMA channels. Please refer to
the specific peripheral chapter for the description
of its interrupt features and control registers.
The on-chip peripheral interrupts are controlled by
the following bits:
– Interrupt Pending bit (IP). Set by hardware
– Interrupt Mask bit (IM). If IM = “0”, no interrupt
– Priority Level (PRL, 3 bits). These bits define
– Interrupt Vector Register (IVR, up to 7 bits).
when the Trigger Event occurs. Can be set/
cleared by software to generate/cancel pending
interrupts and give the status for Interrupt polling.
request is generated. If IM =“1” an interrupt re-
quest is generated whenever IP = “1” and
CICR.IEN = “1”.
the current priority level, PRL=0: the highest pri-
ority, PRL=7: the lowest priority (the interrupt
cannot be acknowledged)
The IVR points to the vector table which itself
contains the interrupt routine start address.
DEDICATED
ON-CHIP
PERIPHERAL