How-To Guide
Table Of Contents
- 29. Low-Power Timer (LPT)
- 29.1 Overview
- 29.2 Register Descriptions
- 29.2.1 Low-Power Timer Control Register 1 (LPTCR1)
- 29.2.2 Low-Power Timer Control Register 2 (LPTCR2)
- 29.2.3 Low-Power Timer Control Register 3 (LPTCR3)
- 29.2.4 Low-Power Timer Period Setting Register (LPTPRD)
- 29.2.5 Low-Power Timer Compare Register 0 (LPCMR0)
- 29.2.6 Low-Power Timer Standby Wakeup Enable Register (LPWUCR)
- 29.3 Operation
- 29.4 Wakeup from Software Standby Mode by an Interrupt through the Event Link Controller (ELC)
- 29.5 Usage Notes
- 30. Watchdog Timer (WDTA)
- 30.1 Overview
- 30.2 Register Descriptions
- 30.3 Operation
- 31. Independent Watchdog Timer (IWDTa)
- 31.1 Overview
- 31.2 Register Descriptions
- 31.3 Operation
- 31.3.1 Count Operation in Each Start Mode
- 31.3.2 Control over Writing to the IWDTCR, IWDTRCR, and IWDTCSTPR Registers
- 31.3.3 Refresh Operation
- 31.3.4 Status Flags
- 31.3.5 Reset Output
- 31.3.6 Interrupt Sources
- 31.3.7 Reading the Counter Value
- 31.3.8 Correspondence between Option Function Select Register 0 (OFS0) and IWDT Registers
- 31.4 Link Operation by ELC
- 31.5 Usage Notes
- 32. USB 2.0 Host/Function Module (USBc)
- 32.1 Overview
- 32.2 Register Descriptions
- 32.2.1 System Configuration Control Register (SYSCFG)
- 32.2.2 System Configuration Status Register 0 (SYSSTS0)
- 32.2.3 Device State Control Register 0 (DVSTCTR0)
- 32.2.4 CFIFO Port Register (CFIFO), D0FIFO Port Register (D0FIFO), D1FIFO Port Register (D1FIFO)
- 32.2.5 CFIFO Port Select Register (CFIFOSEL), D0FIFO Port Select Register (D0FIFOSEL), D1FIFO Port Select Register (D1FIFOSEL)
- 32.2.6 CFIFO Port Control Register (CFIFOCTR), D0FIFO Port Control Register (D0FIFOCTR), D1FIFO Port Control Register (D1FIFOCTR)
- 32.2.7 Interrupt Enable Register 0 (INTENB0)
- 32.2.8 Interrupt Enable Register 1 (INTENB1)
- 32.2.9 BRDY Interrupt Enable Register (BRDYENB)
- 32.2.10 NRDY Interrupt Enable Register (NRDYENB)
- 32.2.11 BEMP Interrupt Enable Register (BEMPENB)
- 32.2.12 SOF Output Configuration Register (SOFCFG)
- 32.2.13 Interrupt Status Register 0 (INTSTS0)
- 32.2.14 Interrupt Status Register 1 (INTSTS1)
- 32.2.15 BRDY Interrupt Status Register (BRDYSTS)
- 32.2.16 NRDY Interrupt Status Register (NRDYSTS)
- 32.2.17 BEMP Interrupt Status Register (BEMPSTS)
- 32.2.18 Frame Number Register (FRMNUM)
- 32.2.19 USB Request Type Register (USBREQ)
- 32.2.20 USB Request Value Register (USBVAL)
- 32.2.21 USB Request Index Register (USBINDX)
- 32.2.22 USB Request Length Register (USBLENG)
- 32.2.23 DCP Configuration Register (DCPCFG)
- 32.2.24 DCP Maximum Packet Size Register (DCPMAXP)
- 32.2.25 DCP Control Register (DCPCTR)
- 32.2.26 Pipe Window Select Register (PIPESEL)
- 32.2.27 Pipe Configuration Register (PIPECFG)
- 32.2.28 Pipe Maximum Packet Size Register (PIPEMAXP)
- 32.2.29 Pipe Cycle Control Register (PIPEPERI)
- 32.2.30 Pipe n Control Registers (PIPEnCTR) (n = 1 to 9)
- 32.2.31 Pipe n Transaction Counter Enable Register (PIPEnTRE) (n = 1 to 5)
- 32.2.32 Pipe n Transaction Counter Register (PIPEnTRN) (n = 1 to 5)
- 32.2.33 Device Address n Configuration Register (DEVADDn) (n = 0 to 5)
- 32.2.34 USB Module Control Register (USBMC)
- 32.2.35 BC Control Register 0 (USBBCCTRL0)
- 32.3 Operation
- 32.3.1 System Control
- 32.3.2 Interrupt Sources
- 32.3.3 Interrupt Descriptions
- 32.3.3.1 BRDY Interrupt
- 32.3.3.2 NRDY Interrupt
- 32.3.3.3 BEMP Interrupt
- 32.3.3.4 Device State Transition Interrupt
- 32.3.3.5 Control Transfer Stage Transition Interrupt
- 32.3.3.6 Frame Update Interrupt
- 32.3.3.7 VBUS Interrupt
- 32.3.3.8 Resume Interrupt
- 32.3.3.9 OVRCR Interrupt
- 32.3.3.10 BCHG Interrupt
- 32.3.3.11 DTCH Interrupt
- 32.3.3.12 SACK Interrupt
- 32.3.3.13 SIGN Interrupt
- 32.3.3.14 ATTCH Interrupt
- 32.3.3.15 EOFERR Interrupt
- 32.3.3.16 Portable Device Detection Interrupt
- 32.3.4 Pipe Control
- 32.3.4.1 Pipe Control Register Switching Procedures
- 32.3.4.2 Transfer Types
- 32.3.4.3 Endpoint Number
- 32.3.4.4 Maximum Packet Size Setting
- 32.3.4.5 Transaction Counter (For Pipes 1 to 5 in Reading Direction)
- 32.3.4.6 Response PID
- 32.3.4.7 Data PID Sequence Bit
- 32.3.4.8 Response PID = NAK Function
- 32.3.4.9 Auto Response Mode
- 32.3.4.10 OUT-NAK Mode
- 32.3.4.11 Null Auto Response Mode
- 32.3.5 FIFO Buffer Memory
- 32.3.6 Control Transfers Using DCP
- 32.3.7 Bulk Transfers (Pipes 1 to 5)
- 32.3.8 Interrupt Transfers (Pipes 6 to 9)
- 32.3.9 Isochronous Transfers (Pipes 1 and 2)
- 32.3.10 SOF Interpolation Function
- 32.3.11 Pipe Schedule
- 32.4 Usage Notes
- 32.5 Battery Charging Detection Processing
- 33. Serial Communications Interface (SCIg, SCIh)
- 33.1 Overview
- 33.2 Register Descriptions
- 33.2.1 Receive Shift Register (RSR)
- 33.2.2 Receive Data Register (RDR)
- 33.2.3 Receive Data Register H, L, HL (RDRH, RDRL, RDRHL)
- 33.2.4 Transmit Data Register (TDR)
- 33.2.5 Transmit Data Register H, L, HL (TDRH, TDRL, TDRHL)
- 33.2.6 Transmit Shift Register (TSR)
- 33.2.7 Serial Mode Register (SMR)
- 33.2.8 Serial Control Register (SCR)
- 33.2.9 Serial Status Register (SSR)
- 33.2.10 Smart Card Mode Register (SCMR)
- 33.2.11 Bit Rate Register (BRR)
R01UH0823EJ0110 Rev.1.10 Page 824 of 1852
Nov 30, 2020
RX23W Group 29. Low-Power Timer (LPT)
29.3 Operation
29.3.1 Periodic Counting Operation
The low-power timer is a 16-bit up-counter that operates regardless of the MCU operating mode*
1
.
When the LPTCR3.LPCNTEN bit is set to 1 (low-power timer counter operates) after setting the
LPTCR1.LPCNTPSSEL[2:0] bits to select the division ratio, the LPTCR1.LPCNTCKSEL bit to select the clock source,
and the LPTCR2.LPCNTSTP bit to 0 (clock is supplied to the low-power timer), the low-power timer counter starts
counting with the selected clock.
When the value of the low-power timer counter matches the value of the LPTPRD register, the counter restarts counting
from 0000h.
When the value of the low-power timer counter matches the value of the LPCMR0 register in software standby mode
while the LPTCR1.LPCMRE0 bit is set to 1 (Compare match 0 is enabled) and the LPWUCR.LPWKUPEN bit is set to
1 (wakeup from software standby mode using low-power timer is enabled), the MCU returns from software standby
mode to normal operating mode by the function of the event link controller (ELC).
Figure 29.2 shows operation of the low-power timer and Figure 29.3 shows an example of procedure for the initial
settings.
Note 1. When the LPTCR1.LPCNTCKSEL bit is set to 1 (IWDT-dedicated clock), the counter stops because the
IWDTCLK stops in the low-power consumption mode under the following settings:
The OFS0.IWDTSLCSTP bit is set to 1 (counting stop is enabled) while IWDT is activated in auto-start mode, or
the IWDTCSTPR.SLCSTP bit is set to 1 (counting stop is enabled) while IWDT is activated in register start mode.
Figure 29.2 Operation of Low-Power Timer
LPTPRD
LPCMR0
0000h
Count starts
Normal
operating mode
Software standby mode
Normal
operating mode
Software standby mode
Normal
operating mode
Software standby
mode
Count value in low-power timer counter
Time
Counter is cleared when count value
matches LPTPRD value
Transitions to software standby
mode by executing WAIT instruction
Transitions to software standby
mode by executing WAIT instruction
Transitions to software standby
mode by executing WAIT instruction
ELC transits to active
state by compare match 0
ELC transits to active
state by compare match 0
ELC generates
interrupt request signal
ELC generates
interrupt request signal
Compare match
signal
MCU operating mode
Interrupt request
signal