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 839 of 1852
Nov 30, 2020
RX23W Group 30. Watchdog Timer (WDTA)
30.3.2 Control over Writing to the WDTCR and WDTRCR Registers
Writing to the WDTCR or WDTRCR register is only possible once between the release from the reset state and the first
refresh operation.
After a refresh operation (counting starts) or by writing to the WDTCR or WDTRCR register, the protection signal in the
WDT becomes 1 to protect the WDTCR and WDTRCR registers against subsequent attempts at writing.
This protection is released by the reset source of the WDT. With other reset sources, the protection is not released.
Figure 30.5 shows control waveforms produced in response to writing to the WDTCR register.
Figure 30.5 Control Waveforms Produced in Response to Writing to the WDTCR Register
30.3.3 Refresh Operation
The down-counter is refreshed by writing the values 00h and then FFh to the WDTRR register. If a value other than FFh
is written after 00h, the down-counter is not refreshed. After such invalid writing, correct refreshing is performed by
again writing to 00h and then FFh to the WDTRR register.
Even if a register other than the WDTRR register is accessed or the WDTRR register is read between writing 00h and
writing FFh to the WDTRR register, correct refreshing will be done.
Writing to refresh the counter must be performed within the refresh-permitted period. Whether writing is done within the
refresh-permitted period is determined when writing FFh. For this reason, correct refreshing will be done even if 00h is
written outside the refresh-permitted period.
[Sample sequences of writing that are valid for refreshing the counter]
• 00h → FFh
• 00h (n–1-th time) → 00h (nth time) → FFh
• 00h → access to another register or read from the WDTRR register → FFh
[Sample sequences of writing that are not valid for refreshing the counter]
• 23h (a value other than 00h) → FFh
• 00h → 54h (a value other than FFh)
• 00h→ AAh (00h and a value other than FFh) → FFh
3300h
WDTCR register is protected
(writing-disabled period)
RES# pin
Peripheral module clock
(PCLK)
Data written to WDTCR
register
WDTCR register write
signal (internal signal)
WDTCR register
Register
protection signal
(internal signal)
xxxxh 00F3h
00F3h33F3h (initial value)
Writing disabled
Writing is possible
00F3h 33F3h (initial value)