STEVAL-ISQ002V1 STMicroelectronics, STEVAL-ISQ002V1 Datasheet - Page 34

• Manufacturer Part Number: STEVAL-ISQ002V1
• Description: BOARD EVAL BASED ON ST72264G1
• Manufacturer: STMicroelectronics

Specifications of STEVAL-ISQ002V1

• Main Purpose: Interface, PMBus
• Embedded: Yes, MCU, 8-Bit
• Utilized Ic / Part: ST72F264
• Primary Attributes: The PMBus™ Interface Using the ST7 I2C Peripheral
• Secondary Attributes: Firmware in C Language
• Product: Power Management Modules
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: 497-6423

ST72260Gx, ST72262Gx, ST72264Gx
POWER SAVING MODES (Cont’d)
8.3 WAIT MODE
WAIT mode places the MCU in a low power con-
sumption mode by stopping the CPU.
This power saving mode is selected by calling the
“WFI” ST7 software instruction.
All peripherals remain active. During WAIT mode,
the I [1:0] bits in the CC register are forced to ‘10b’ ,
to enable all interrupts. All other registers and
memory remain unchanged. The MCU remains in
WAIT mode until an interrupt or Reset occurs,
whereupon the Program Counter branches to the
starting address of the interrupt or Reset service
routine.
The MCU will remain in WAIT mode until a Reset
or an Interrupt occurs, causing it to wake up.
Refer to
34/172
Figure
22.
Figure 22. WAIT Mode Flowchart
Note:
1. Before servicing an interrupt, the CC register is
pushed on the stack. The I[1:0] bits in the CC reg-
ister are set during the interrupt routine and
cleared when the CC register is popped.
WFI INSTRUCTION
N
INTERRUPT
Y
OR SERVICE INTERRUPT
FETCH RESET VECTOR
4096 CPU CLOCK CYCLE
OSCILLATOR
PERIPHERALS
CPU
I[1:0] BITS
OSCILLATOR
PERIPHERALS
CPU
I[1:0] BITS
OSCILLATOR
PERIPHERALS
CPU
I[1:0] BITS
N
DELAY
RESET
Y
XX
OFF
OFF
ON
ON
ON
ON
ON
ON
ON
0
1
1)