Followings are hardware connection and test samples for Y-RH850-U2C-292PIN-PB-T1-V1, for more detail on how to setup hardware connection, please visit RH850/U2C 292pin User's Manual: Piggyback Board .

Default UART Connection

HW	Configurations	Remark
UART0_TX (P04_1)	CN14_5	connect to USB-TTL module RX pin
UART0_RX (P04_2)	CN14_7	connect to USB-TTL module TX pin

The UART port can be accessed by connecting a USB-to-TTL converter to the UART0 TX and RX pins.

Flash Command

Before using the flash command, follow this guide to install the Renesas Flash Programmer (RFP) Host Tools.
Then, use the following command to flash the code to the board:
- west flash -- --tool-opt="-auth id FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF -osc 20"

UART Sample

echo_bot (samples/drivers/uart/echo_bot):
- Hardware configuration: refer to default UART connection.
- Build command:
  - west build -p always -b pb_rh850u2c_292pin/r7f702600afabb-c samples/drivers/uart/echo_bot
zTest uart_basic_api (tests/drivers/uart/uart_basic_api):
- Hardware configuration: refer to default UART connection.
- Build command:
  - west build -p always -b pb_rh850u2c_292pin/r7f702600afabb-c tests/drivers/uart/uart_basic_api

GPIO Sample

Blinky (samples/basic/blinky): Simple LED blinky
- Hardware configuration:
  
  LED Signal Jumper Configuration
  
  LED10 CN11 Jumper on pins 1-2
- Build command: $ west build -p always -b pb_rh850u2c_292pin/r7f702600afabb-c samples/basic/blinky
zTest gpio_api_1pin (tests/drivers/gpio/gpio_api_1pin):
- Hardware configuration: No additional connection
- Build command: west build -p always -b pb_rh850u2c_292pin/r7f702600afabb-c tests/drivers/gpio/gpio_api_1pin
zTest gpio_basic_api (tests/drivers/gpio/gpio_basic_api):
- Hardware configuration:
  
  HW Board Pin Configurations
  
  P02_4 CN14_36 Connect to P02_5 (CN14_37)
- Build command: west build -p always -b pb_rh850u2c_292pin/r7f702600afabb-c tests/drivers/gpio/gpio_basic_api

LED Signal	Jumper	Configuration
LED10	CN11	Jumper on pins 1-2

HW	Board Pin	Configurations
P02_4	CN14_36	Connect to P02_5 (CN14_37)

Ethernet Sample

1. Hardware Configuration

Board

RH850,R-Car U5x Common Main board
Ethernet Extension Board for 10BASE-T1S
Renesas Y-RH850-U2C-292PIN-PB-T1-V1 (r7f702600afabb)
Ethernet T1S interface connected to ETNF0 peripheral

Required Connections — ETNF0 Pin Mapping

Signal	Port Pin	Alternate Function	Description
ETNF0 pin	PORT_20 pin 4	ALT_OUT3	Ethernet T1S signal
ETNF0 pin	PORT_20 pin 11	ALT_OUT3	Ethernet T1S signal
ETNF0 pin	PORT_22 pin 2	ALT_OUT2	Ethernet T1S signal
ETNF0 pin (direct)	PORT_20 pin 3	ALT_OUT3	Ethernet T1S signal
ETNF0 pin (direct)	PORT_20 pin 13	ALT_OUT4	Ethernet T1S signal
ETNF0 pin (direct)	PORT_21 pin 0	ALT_OUT2	Ethernet T1S signall

Pin Control DTS

Defined in pb_rh850u2c_292pin_r7f702600afabb-pinctrl.dtsi:

etnf0_default: etnf0_default {
    group1 {
        psels = <RH850_PSEL(PORT_20, 4, ALT_OUT3)>,
                <RH850_PSEL(PORT_20, 11, ALT_OUT3)>,
                <RH850_PSEL(PORT_22, 2, ALT_OUT2)>;
        drive-strength = "high";
    };
    group2 {
        psels = <RH850_PSEL(PORT_20, 3, ALT_OUT3)>,
                <RH850_PSEL(PORT_20, 13, ALT_OUT4)>,
                <RH850_PSEL(PORT_21, 0, ALT_OUT2)>;
        drive-strength = "high";
        renesas,direct-control;
    };
};

PHY Configuration

Parameter	Value
PHY Type	CT25205 (T1S PHY)
PHY Address	31
Flow Control	Disabled
Network Speed	10 Mbps

Driver Kconfig Parameters

Config Symbol	Default	Range	Description
`CONFIG_ETH_RENESAS_RCARMCU`	y (auto)	—	Enable Renesas RH850/U2C Ethernet ETNF driver
`CONFIG_ETH_RENESAS_RX_THREAD_STACK_SIZE`	1500	—	RX handler thread stack size (bytes)
`CONFIG_ETH_RENESAS_RX_THREAD_PRIORITY`	2	—	RX thread cooperative priority
`CONFIG_ETH_RENESAS_TX_BUF_NUM`	4	1–8	Number of TX descriptors
`CONFIG_ETH_RENESAS_RX_BUF_NUM`	4	1–8	Number of RX descriptors

DTS Node Reference

The ETNF0 peripheral node in r7f7026xx.dtsi:

/* ETNF0 MAC node */
etnf0: ethernet@ff1d0000 {
    compatible = "renesas,rcarmcu-ethernet-etnf";
    reg = <0xff1d0000 0x77c>;
    interrupts = <536 0>;
    interrupt-parent = <&intc2>;
    phy-connection-type = "internal";
    mdio-interface = "shared";
    pma-filtered;
    status = "disabled";

    ct25205: phy {
        compatible = "renesas,ct25205-phy";
        phy-lsi-addr = <31>;
        plca-enable;
        plca-node-id = <0>;
        plca-node-count = <8>;
        plca-burst-count = <0>;
        plca-burst-timer = <128>;
        plca-to-timer = <32>;
        status = "okay";
    };
};

Enabled in pb_rh850u2c_292pin_r7f702600afabb.dts:

&etnf0 {
    pinctrl-0 = <&etnf0_default>;
    pinctrl-names = "default";
    status = "okay";
};

2. IAR Toolchain — Known Limitation

Zephyr's POSIX socket layer (CONFIG_POSIX_API) is not supported with the IAR toolchain on RH850/U2C. The following components are therefore skipped on this platform:

Category	Affected Component	Status
Zephyr net/sockets samples	All of `samples/net/sockets/*` (including `http_get`, `http_client`, `echo_server`, etc.)	Skipped — cannot build with IAR
Third-party POSIX libraries	Paho MQTT C client (`samples/net/mqtt_sn_publisher`) and any library depending on POSIX socket headers	Skipped — cannot build with IAR
SNTP	`samples/net/sntp` (Zephyr version dependent)	Skipped — may not build with IAR
Socket API	Customer code using `socket()`, `recv()`, `send()`, `close()`, `poll()`, `select()`, `fcntl()`	Not portable — requires Zephyr native BSD socket API
Linux/POSIX code ports	Customer code ported from Linux or other POSIX environments	Requires porting effort to Zephyr native socket API

Samples validated with IAR on RH850/U2C:

samples/net/zperf
samples/net/dhcpv4_client

3. Sample Application — `samples/net/zperf`

The zperf sample is an Ethernet network benchmark tool that measures upload and download throughput using TCP or UDP. It relies on DHCPv4 to obtain an IP address automatically.

Board-specific files added:

samples/net/zperf/boards/pb_rh850u2c_292pin_r7f702600afabb.conf

Build command:

west build -p always -b pb_rh850u2c_292pin/r7f702600afabb samples/net/zperf

Board config (pb_rh850u2c_292pin_r7f702600afabb.conf):

CONFIG_NET_DHCPV4=y
CONFIG_NET_IPV6=n
CONFIG_NET_CONFIG_MY_IPV4_ADDR=""
CONFIG_NET_CONFIG_PEER_IPV4_ADDR=""
CONFIG_NET_PKT_RX_COUNT=10
CONFIG_NET_PKT_TX_COUNT=10
CONFIG_NET_BUF_RX_COUNT=30
CONFIG_NET_BUF_TX_COUNT=30
CONFIG_NET_BUF_DATA_SIZE=512
CONFIG_POSIX_API=n

Expected Output

After boot, the board acquires an IP via DHCPv4 and the Zephyr shell becomes available. The boot sequence observed:

[00:00:00.000,000] <inf> eth_renesas_etnf: ETNF0 10BASE-T1S driver initialized
[00:00:00.026,000] <inf> phy_renesas_ct25205: PHY CT25205 Initialized
*** Booting Zephyr OS build v4.3.0-2T58-gdb608d403e81 ***
[00:00:00.026,000] <inf> net_config: Initializing network
[00:00:00.026,000] <inf> net_config: Waiting interface 1 (0xfe003d70) to be up...
[00:00:00.527,000] <inf> eth_renesas_etnf: Link UP — 10BASE-T1S half-duplex 10 Mbps
[00:00:00.527,000] <inf> net_config: Interface 1 (0xfe003d70) coming up
[00:00:00.528,000] <inf> net_config: Running dhcpv4 client...
[00:00:06.540,000] <inf> net_dhcpv4: Received: 192.168.10.11
[00:00:06.540,000] <inf> net_config: IPv4 address: 192.168.10.11
[00:00:06.540,000] <inf> net_config: Lease time: 43200 seconds
[00:00:06.540,000] <inf> net_config: Subnet: 255.255.255.0
[00:00:06.540,000] <inf> net_config: Router: 192.168.10.1

Run zperf commands from the shell:

TCP Upload — zperf tcp upload <server_ip> <port> <duration_s> <packet_size>:

uart:~$ zperf tcp upload 192.168.10.1 5001 10 1K
Remote port is 5001
Connecting to 192.168.10.1
Duration:     10.00 s
Packet size:  1000 bytes
Rate:         10 Kbps
Starting...
-
Upload completed!
Duration:      10.00 s
Num packets:   11071
Num errors:    0 (retry or fail)
Rate:          8.85 Mbps

TCP Upload evidence

TCP Download — zperf tcp download <port> <server_ip>:

# Zephyr
uart:~$ zperf tcp download 5001 192.168.10.11
New TCP session started.
TCP session ended
  Duration:   10.32 s
  rate:       9.24 Mbps
New TCP session started.
TCP session ended
  Duration:   10.33 s
  rate:       9.23 Mbps
New TCP session started.
TCP session ended
  Duration:   10.32 s
  rate:       9.24 Mbps
New TCP session started.
TCP session ended
  Duration:   10.33 s
  rate:       9.23 Mbps

TCP Download evidence

UDP Download — zperf udp download <port> <server_ip>:

uart:~$ zperf udp download 5001 192.168.10.11
UDP server started on port 5001
[00:00:51.025,000] <inf> net_zperf: Binding to 192.168.10.11
[00:00:51.025,000] <inf> net_zperf: Listening on port 5001
New session started.
End of session!
 duration:            10.07 s
 received packets:    11486
 nb packets lost:     7
 nb packets outorder: 0
 jitter:              2.78 ms
 rate:                9.34 Mbps
New session started.
End of session!
 duration:            10.06 s
 received packets:    11482
 nb packets lost:     6
 nb packets outorder: 0
 jitter:              2.80 ms
 rate:                9.34 Mbps

UDP Download evidence

UDP Upload — zperf udp upload <server_ip> <port> <duration_s> <packet_size> <rate>:

uart:~$ zperf udp upload 192.168.10.1 5001 10 1K 10M
Remote port is 5001
Connecting to 192.168.10.1
Duration:     10.00 s
Packet size:  1000 bytes
Rate:         10.00 Mbps
Starting...
Rate:         10.00 Mbps
Packet duration 781 us
-
Upload completed!
Statistics:            server    (client)
Duration:              9.99 s    (10.00 s)
Num packets:           11485     (11485)
Num packets out order: 0
Num packets lost:      0
Jitter:                855 us
Rate:                  9.18 Mbps    (9.18 Mbps)
uart:~$ zperf udp upload 192.168.10.1 5001 10 1K 10M
Remote port is 5001
Connecting to 192.168.10.1
Duration:     10.00 s
Packet size:  1000 bytes
Rate:         10.00 Mbps
Starting...
Rate:         10.00 Mbps
Packet duration 781 us
-
Upload completed!
Statistics:            server    (client)
Duration:              10.00 s    (10.00 s)
Num packets:           11493     (11493)
Num packets out order: 0
Num packets lost:      0
Jitter:                855 us
Rate:                  9.18 Mbps    (9.18 Mbps)

UDP Upload evidence

4. Sample Application — `samples/net/dhcpv4_client`

The dhcpv4_client sample demonstrates automatic IPv4 address acquisition via DHCPv4 on the Ethernet T1S interface. No overlay is required — the existing board support for pb_rh850u2c_292pin_r7f702600afabb is sufficient.

Build command:

west build -p always -b pb_rh850u2c_292pin/r7f702600afabb samples/net/dhcpv4_client

Expected Output

dhcpv4_client evidence

Note: The warning DHCP server provided more DNS servers than can be saved is non-critical and does not affect DHCPv4 functionality.

RH850‐U2C‐292PIN Sample and Demo hardware configuration - renesas/zephyr GitHub Wiki

Table of contents

Default UART Connection

Flash Command

UART Sample

GPIO Sample

Ethernet Sample

1. Hardware Configuration

Board

Required Connections — ETNF0 Pin Mapping

Pin Control DTS

PHY Configuration

Driver Kconfig Parameters

DTS Node Reference

2. IAR Toolchain — Known Limitation

3. Sample Application — `samples/net/zperf`

Expected Output

4. Sample Application — `samples/net/dhcpv4_client`

Expected Output

⚠️ GitHub.com Fallback ⚠️

RH850‐U2C‐292PIN Sample and Demo hardware configuration - renesas/zephyr GitHub Wiki

Table of contents

Default UART Connection

Flash Command

UART Sample

GPIO Sample

Ethernet Sample

1. Hardware Configuration

Board

Required Connections — ETNF0 Pin Mapping

Pin Control DTS

PHY Configuration

Driver Kconfig Parameters

DTS Node Reference

2. IAR Toolchain — Known Limitation

3. Sample Application — samples/net/zperf

Expected Output

4. Sample Application — samples/net/dhcpv4_client

Expected Output

⚠️ **GitHub.com Fallback** ⚠️

3. Sample Application — `samples/net/zperf`

4. Sample Application — `samples/net/dhcpv4_client`

⚠️ GitHub.com Fallback ⚠️