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 828 of 1852
Nov 30, 2020
RX23W Group 30. Watchdog Timer (WDTA)
30. Watchdog Timer (WDTA)
The watchdog timer (WDT) is a 14-bit down-counter. It can be used to reset this MCU when the counter underflows
because its value cannot be refreshed due to the system being out of control.
In addition, a non-maskable interrupt can be generated by an underflow.
The refresh-permitted period can be set to refresh the counter and used as the condition to detect when the system runs
out of control.
In this section, “PCLK” is used to refer to PCLKB.
30.1 Overview
Table 30.1 lists the specifications of the WDT and Figure 30.1 shows a block diagram of the WDT.
Figure 30.1 WDT Block Diagram
Table 30.1 WDT Specifications
Item Specifications
Count source Peripheral module clock (PCLK)
Clock division ratio Divide by 4, 64, 128, 512, 2048, or 8192
Counter operation Counting down using a 14-bit down-counter
Conditions for starting the counter
• Auto-start mode: Counting automatically starts after a reset is released
• Register start mode: Counting is started by refresh operation (writing 00h and then FFh to the
WDTRR register)
Conditions for stopping the
counter
• Reset (the down-counter and other registers return to their initial values)
• In low power consumption states
• A counter underflows or a refresh error occurs (only in register start mode)
Window function Window start and end positions can be specified (refresh-permitted and refresh-prohibited periods)
Watchdog timer
Reset sources
• Down-counter underflows
• Refreshing outside the refresh-permitted period (refresh error)
Non-maskable interrupt sources
• Down-counter underflows
• Refreshing outside the refresh-permitted period (refresh error)
Reading the counter value The down-counter value can be read by the WDTSR register.
Internal peripheral bus
WDT control circuit 14-bit down-counter
WDTRR: WDT refresh register
WDTCR: WDT control register
WDTSR: WDT status register
WDTRCR: WDT reset control register
WDT reset
Interrupt request (WUNI)
Option function select register 0
(OFS0)
PCLK/4
PCLK/64
PCLK/512
PCLK/128
PCLK/2048
PCLK/8192
PCLK
Clock
frequency
divider
WDTRCR
WDTSR
WDTCR
WDTRR