Application Note
R01AN4800EJ0120 Rev.1.20 Page 1 of 86
Nov.05.21
RX23W Group, RX230/RX231 Group
Differences Between the RX23W Group and the RX231 Group
Summary
This application note is intended as a reference to points of difference between the peripheral functions, I/O
registers, and pin functions of the RX23W Group and RX231 Group, as well as a guide to key points to
consider when migrating between the two groups.
Unless specifically otherwise noted, the information in this application note applies to the 85-pin package
version of the RX23W Group and the 100-pin package version and chip version B of the RX231 Group. To
confirm details of differences in the specifications of the electrical characteristics, usage notes, and setting
procedures, refer to the User’s Manual: Hardware of the products in question.
Target Devices
RX23W Group and RX231 Group
RX23W Group, RX230/RX231 Group Differences Between the RX23W Group and the RX231 Group
R01AN4800EJ0120 Rev.1.20 Page 2 of 86
Nov.05.21
Contents
1. Comparison of Built-In Functions of RX23W Group and RX231 Group .................................... 4
2. Comparative Overview of Specifications .................................................................................. 6
2.1 Operating Modes ..................................................................................................................................... 6
2.2 Resets ..................................................................................................................................................... 7
2.3 Option-Setting Memory ........................................................................................................................... 8
2.4 Voltage Detection Circuit ......................................................................................................................... 9
2.5 Clock Generation Circuit ....................................................................................................................... 12
2.6 Low Power Consumption ...................................................................................................................... 15
2.7 Register Write Protection Function ........................................................................................................ 16
2.8 Interrupt Controller................................................................................................................................. 17
2.9 Buses ..................................................................................................................................................... 19
2.10 Event Link Controller ............................................................................................................................. 21
2.11 I/O Ports ................................................................................................................................................ 24
2.12 Multi-Function Pin Controller ................................................................................................................. 26
2.13 Multi-Function Timer Pulse Unit 2 ......................................................................................................... 40
2.14 Port Output Enable 2 ............................................................................................................................. 42
2.15 16-Bit Timer Pulse Unit ......................................................................................................................... 44
2.16 8-Bit Timer ............................................................................................................................................. 46
2.17 Realtime Clock ...................................................................................................................................... 47
2.18 USB 2.0 Host/Function Module ............................................................................................................. 48
2.19 Serial Communications Interface .......................................................................................................... 49
2.20 Serial Peripheral Interface ..................................................................................................................... 53
2.21 Capacitive Touch Sensing Unit ............................................................................................................. 56
2.22 12-Bit A/D Converter ............................................................................................................................. 62
2.23 12-Bit D/A Converter ............................................................................................................................. 67
2.24 Comparator B ........................................................................................................................................ 68
2.25 RAM ....................................................................................................................................................... 70
2.26 Flash Memory ........................................................................................................................................ 71
2.27 Packages ............................................................................................................................................... 73
3. Comparison of Pin Functions ................................................................................................. 74
3.1 100-Pin Package (RX231: TFLGA)/85-Pin Package (RX23W: BGA) ................................................... 74
3.2 64-Pin Package (RX231: HWQFN)/56-Pin Package (RX23W: QFN) ................................................... 79
4. Notes on Migration................................................................................................................. 82
4.1 Operating Voltage Range ...................................................................................................................... 82
4.1.1 Power Supply Voltage ......................................................................................................................... 82
4.2 Notes on Function Settings ................................................................................................................... 83
4.2.1 Limitations Applying to I/O Port Register Settings .............................................................................. 83
4.2.2 8-Bit Timer Cascaded Operation ......................................................................................................... 83