User's Manual
Table Of Contents
- Cover
- Notice
- General Precautions in the Handling of Microprocessing Unit and Microcontroller Unit Products
- How to Use This Manual
- Contents
- Features
- 1. Overview
- 2. CPU
- 2.1 Features
- 2.2 Register Set of the CPU
- 2.2.1 General-Purpose Registers (R0 to R15)
- 2.2.2 Control Registers
- 2.2.2.1 Interrupt Stack Pointer (ISP)/User Stack Pointer (USP)
- 2.2.2.2 Exception Table Register (EXTB)
- 2.2.2.3 Interrupt Table Register (INTB)
- 2.2.2.4 Program Counter (PC)
- 2.2.2.5 Processor Status Word (PSW)
- 2.2.2.6 Backup PC (BPC)
- 2.2.2.7 Backup PSW (BPSW)
- 2.2.2.8 Fast Interrupt Vector Register (FINTV)
- 2.2.2.9 Floating-Point Status Word (FPSW)
- 2.2.3 Accumulator
- 2.3 Processor Mode
- 2.4 Data Types
- 2.5 Endian
- 2.6 Vector Table
- 2.7 Operation of Instructions
- 2.8 Number of Cycles
- 3. Operating Modes
- 4. Address Space
- 5. I/O Registers
- 6. Resets
- 7. Option-Setting Memory (OFSM)
- 8. Voltage Detection Circuit (LVDAb)
- 9. Clock Generation Circuit
- 9.1 Overview
- 9.2 Register Descriptions
- 9.2.1 System Clock Control Register (SCKCR)
- 9.2.2 System Clock Control Register 3 (SCKCR3)
- 9.2.3 PLL Control Register (PLLCR)
- 9.2.4 PLL Control Register 2 (PLLCR2)
- 9.2.5 USB-dedicated PLL Control Register (UPLLCR)
- 9.2.6 USB-dedicated PLL Control Register 2 (UPLLCR2)
- 9.2.7 Main Clock Oscillator Control Register (MOSCCR)
- 9.2.8 Sub-Clock Oscillator Control Register (SOSCCR)
- 9.2.9 Low-Speed On-Chip Oscillator Control Register (LOCOCR)
- 9.2.10 IWDT-Dedicated On-Chip Oscillator Control Register (ILOCOCR)
- 9.2.11 High-Speed On-Chip Oscillator Control Register (HOCOCR)
- 9.2.12 High-Speed On-Chip Oscillator Control Register 2 (HOCOCR2)
- 9.2.13 Oscillation Stabilization Flag Register (OSCOVFSR)
- 9.2.14 Oscillation Stop Detection Control Register (OSTDCR)
- 9.2.15 Oscillation Stop Detection Status Register (OSTDSR)
- 9.2.16 Main Clock Oscillator Wait Control Register (MOSCWTCR)
- 9.2.17 CLKOUT Output Control Register (CKOCR)
- 9.2.18 Main Clock Oscillator Forced Oscillation Control Register (MOFCR)
- 9.2.19 Memory Wait Cycle Setting Register (MEMWAIT)
- 9.2.20 Low-Speed On-Chip Oscillator Trimming Register (LOCOTRR)
- 9.2.21 IWDT-Dedicated On-Chip Oscillator Trimming Register (ILOCOTRR)
- 9.2.22 High-Speed On-Chip Oscillator Trimming Register n (HOCOTRRn) (n = 0, 3)
- 9.3 Main Clock Oscillator
- 9.4 Sub-Clock Oscillator
- 9.5 Dedicated Clock Oscillator for Bluetooth
- 9.6 Oscillation Stop Detection Function
- 9.7 PLL Circuit
- 9.8 Internal Clock
- 9.9 Usage Notes
- 10. Clock Frequency Accuracy Measurement Circuit (CAC)
- 10.1 Overview
- 10.2 Register Descriptions
- 10.2.1 CAC Control Register 0 (CACR0)
- 10.2.2 CAC Control Register 1 (CACR1)
- 10.2.3 CAC Control Register 2 (CACR2)
- 10.2.4 CAC Interrupt Request Enable Register (CAICR)
- 10.2.5 CAC Status Register (CASTR)
- 10.2.6 CAC Upper-Limit Value Setting Register (CAULVR)
- 10.2.7 CAC Lower-Limit Value Setting Register (CALLVR)
- 10.2.8 CAC Counter Buffer Register (CACNTBR)
- 10.3 Operation
- 10.4 Interrupt Requests
- 10.5 Usage Notes
- 11. Low Power Consumption
- 11.1 Overview
- 11.2 Register Descriptions
- 11.2.1 Standby Control Register (SBYCR)
- 11.2.2 Module Stop Control Register A (MSTPCRA)
- 11.2.3 Module Stop Control Register B (MSTPCRB)
- 11.2.4 Module Stop Control Register C (MSTPCRC)
- 11.2.5 Module Stop Control Register D (MSTPCRD)
- 11.2.6 Operating Power Control Register (OPCCR)
- 11.2.7 Sub Operating Power Control Register (SOPCCR)
- 11.2.8 Sleep Mode Return Clock Source Switching Register (RSTCKCR)
- 11.3 Reducing Power Consumption by Switching Clock Signals
- 11.4 Module Stop Function
- 11.5 Function for Lower Operating Power Consumption
- 11.6 Low Power Consumption Modes
- 11.7 Usage Notes
- 12. Battery Backup Function
- 13. Register Write Protection Function
- 14. Exception Handling
- 15. Interrupt Controller (ICUb)
- 15.1 Overview
- 15.2 Register Descriptions
- 15.2.1 Interrupt Request Register n (IRn) (n = interrupt vector number)
- 15.2.2 Interrupt Request Enable Register m (IERm) (m = 02h to 1Fh)
- 15.2.3 Interrupt Source Priority Register n (IPRn) (n = interrupt vector number)
- 15.2.4 Fast Interrupt Set Register (FIR)
- 15.2.5 Software Interrupt Generation Register (SWINTR)
- 15.2.6 DTC Transfer Request Enable Register n (DTCERn) (n = interrupt vector number)
- 15.2.7 DMAC Trigger Select Register m (DMRSRm) (m = DMAC channel number)
- 15.2.8 IRQ Control Register i (IRQCRi) (i = 0, 1, and 4 to 7)
- 15.2.9 IRQ Pin Digital Filter Enable Register 0 (IRQFLTE0)
- 15.2.10 IRQ Pin Digital Filter Setting Register 0 (IRQFLTC0)
- 15.2.11 Non-Maskable Interrupt Status Register (NMISR)
- 15.2.12 Non-Maskable Interrupt Enable Register (NMIER)
- 15.2.13 Non-Maskable Interrupt Status Clear Register (NMICLR)
- 15.2.14 NMI Pin Interrupt Control Register (NMICR)
- 15.2.15 NMI Pin Digital Filter Enable Register (NMIFLTE)
- 15.2.16 NMI Pin Digital Filter Setting Register (NMIFLTC)
- 15.3 Vector Table
- 15.4 Interrupt Operation
- 15.5 Non-maskable Interrupt Operation
- 15.6 Return from Power-Down States
- 15.7 Usage Note
- 16. Buses
- 17. Memory-Protection Unit (MPU)
- 17.1 Overview
- 17.2 Register Descriptions
- 17.2.1 Region-n Start Page Number Register (RSPAGEn) (n = 0 to 7)
- 17.2.2 Region-n End Page Number Register (REPAGEn) (n = 0 to 7)
- 17.2.3 Memory-Protection Enable Register (MPEN)
- 17.2.4 Background Access Control Register (MPBAC)
- 17.2.5 Memory-Protection Error Status-Clearing Register (MPECLR)
- 17.2.6 Memory-Protection Error Status Register (MPESTS)
- 17.2.7 Data Memory-Protection Error Address Register (MPDEA)
- 17.2.8 Region Search Address Register (MPSA)
- 17.2.9 Region Search Operation Register (MPOPS)
- 17.2.10 Region Invalidation Operation Register (MPOPI)
- 17.2.11 Instruction-Hit Region Register (MHITI)
- 17.2.12 Data-Hit Region Register (MHITD)
- 17.3 Functions
- 17.4 Procedures for Using Memory Protection
- 18. DMA Controller (DMACA)
- 18.1 Overview
- 18.2 Register Descriptions
- 18.2.1 DMA Source Address Register (DMSAR)
- 18.2.2 DMA Destination Address Register (DMDAR)
- 18.2.3 DMA Transfer Count Register (DMCRA)
- 18.2.4 DMA Block Transfer Count Register (DMCRB)
- 18.2.5 DMA Transfer Mode Register (DMTMD)
- 18.2.6 DMA Interrupt Setting Register (DMINT)
- 18.2.7 DMA Address Mode Register (DMAMD)
- 18.2.8 DMA Offset Register (DMOFR)
- 18.2.9 DMA Transfer Enable Register (DMCNT)
- 18.2.10 DMA Software Start Register (DMREQ)
- 18.2.11 DMA Status Register (DMSTS)
- 18.2.12 DMA Activation Source Flag Control Register (DMCSL)
- 18.2.13 DMA Module Activation Register (DMAST)
- 18.3 Operation
- 18.4 Ending DMA Transfer
- 18.5 Interrupts
- 18.6 Event Link Function
- 18.7 Low Power Consumption Function
- 18.8 Usage Notes
- 18.8.1 DMA Transfer to Peripheral Modules
- 18.8.2 Access to the Registers during DMA Transfer
- 18.8.3 DMA Transfer to Reserved Areas
- 18.8.4 Interrupt Request by the DMA Activation Source Flag Control Register (DMCSL) at the End of each Transfer
- 18.8.5 Setting of DMAC Activation Source Select Register of the Interrupt Controller (ICU.DMRSRm)
- 18.8.6 Suspending or Restarting DMA Activation
- 19. Data Transfer Controller (DTCa)
- 19.1 Overview
- 19.2 Register Descriptions
- 19.2.1 DTC Mode Register A (MRA)
- 19.2.2 DTC Mode Register B (MRB)
- 19.2.3 DTC Transfer Source Register (SAR)
- 19.2.4 DTC Transfer Destination Register (DAR)
- 19.2.5 DTC Transfer Count Register A (CRA)
- 19.2.6 DTC Transfer Count Register B (CRB)
- 19.2.7 DTC Control Register (DTCCR)
- 19.2.8 DTC Vector Base Register (DTCVBR)
- 19.2.9 DTC Address Mode Register (DTCADMOD)
- 19.2.10 DTC Module Start Register (DTCST)
- 19.2.11 DTC Status Register (DTCSTS)
- 19.3 Request Sources
- 19.4 Operation
R01UH0823EJ0110 Rev.1.10 Page 212 of 1852
Nov 30, 2020
RX23W Group 9. Clock Generation Circuit
9.9 Usage Notes
9.9.1 Notes on Clock Generation Circuit
(1) The frequencies of the system clock (ICLK), peripheral module clocks (PCLKA, PCLKB, and PCLKD), and
FlashIF clock (FCLK) supplied to each module can be selected by the SCKCR register. Each frequency should meet
the following:
Select each frequency that is within the operation guaranteed range of clock cycle time (tcyc) specified in AC
characteristics of electrical characteristics.
The frequencies must not exceed the ranges listed in Table 9.1.
The peripheral modules operate on the PCLKA, PCLKB and PCLKD. Note therefore that the operating speed of
modules such as the timer and SCI varies before and after the frequency is changed.
(2) The relationship of frequencies of the system clock (ICLK), peripheral module clocks A, B, and D (PCLKA,
PCLKB, and PCLKD), and FlashIF clock (FCLK) must be set as follows.
ICLK:FCLK = N:1 or 1:N (N is an integer)
ICLK:PCLKA, PCLKB, and PCLKD = N:1 or 1:N (N is an integer)
(3) To secure the processing after the clock frequency is changed, modify the pertinent clock control register to change
the frequency, and then read the value from the register, and then perform the subsequent processing.
9.9.2 Note on Rewriting the SCKCR3 Register
When the SCKCR3.CKSEL[2:0] bits have been rewritten, the clock output is temporarily stopped to prevent the switch
of the clock source from generating a clock pulse of short duration (glitch). The interrupt controller and event link
controller may not detect the following signals that were input during this period.
(1) An external pin interrupt or NMI pin interrupt with a pulse width shorter than 4 cycles of the PCLKB after the
switch while the PCLKB frequency is the 1/1 of the clock source (the SCKCR.PCKB[3:0] bits are 0000b).
(2) An external pin interrupt or NMI pin interrupt with a pulse width shorter than 2.5 cycles of the PCLKB after the
switch while the PCLKB frequency is the 1/2 of the clock source (the SCKCR.PCKB[3:0] bits are 0001b).
(3) An RTC periodic interrupt or RTC periodic event output when the SCKCR3.CKSEL[2:0] bits are changed to
“011b” (sub-clock).
When the external pin interrupt or NMI pin interrupt is in use, input the signal with enough pulse width to exceed the
time condition described in (1) and (2). When the RTC periodic interrupt or RTC periodic event output is in use, switch
the clock source after a periodic interrupt is generated and before the next periodic interrupt is generated.
9.9.3 Notes on Resonator
Since various resonator characteristics relate closely to the user's board design, adequate evaluation is required on the
user side before use, referencing the resonator connection example shown in this section. The circuit constants for the
resonator depend on the resonator to be used and the stray capacitance of the mounting circuit. Therefore, the circuit
constants should be determined in full consultation with the resonator manufacturer. The voltage to be applied between
the resonator pins must be within the absolute maximum rating.
9.9.4 Notes on Board Design
When using a crystal, place the resonator and its load capacitors as close to the XTAL and EXTAL pins as possible.
Other signal lines should be routed away from the oscillation circuit as shown in Figure 9.14 to prevent electromagnetic
induction from interfering with correct oscillation.