Hi everybody,

Does anyone know the purpose of this register and how it woks? (H3 datashhet, p321)
It seems related to open drain strength (0 to 3, current limiting), but i'm really not sure.

I dumbed the value of gpio register and here is what i get just after armbian boot (below)
microsd and interrnal power control use level 2 and 3 instead of default level 1 for all other pins

If anybody knows, i'm interested before destroying my NanoPi Neo while playing with those registers...

Code: Select all

PA00:   UART2_TX    Pull-up level 1, value OFF CON1_PIN11
PA01:   UART2_RX    Pull-up level 1, value OFF CON1_PIN22
PA02:          -          - level 1, value OFF CON1_PIN13
PA03:          -          - level 1, value OFF CON1_PIN15
PA04:   UART0_TX    Pull-up level 1, value OFF DBUG_PIN03
PA05:   UART0_RX    Pull-up level 1, value OFF DBUG_PIN04
PA06:          -          - level 1, value OFF CON1_PIN12
PA07:          -          - level 1, value OFF
PA08:          -          - level 1, value OFF
PA09:          -          - level 1, value OFF
PA10:     OUTPUT          - level 1, value OFF BLUE_LED
PA11:   TWI0_SCK          - level 1, value OFF CON1_PIN05
PA12:   TWI0_SDA          - level 1, value OFF CON1_PIN03
PA13:   UART3_TX    Pull-up level 1, value OFF
PA14:   UART3_RX    Pull-up level 1, value OFF
PA15:          -          - level 1, value OFF
PA16:     OUTPUT          - level 1, value ON
PA17:          -          - level 1, value OFF CON2_PIN07
PA18:   TWI1_SCK          - level 1, value OFF CON2_PIN08
PA19:   TWI1_SDA          - level 1, value OFF CON2_PIN09
PA20:          -          - level 1, value OFF CON2_PIN10
PA21:          -          - level 1, value OFF CON2_PIN11
PC00:  SPI0_MOSI          - level 1, value OFF CON1_PIN19
PC01:  SPI0_MISO          - level 1, value OFF CON1_PIN21
PC02:   SPI0_CLK          - level 1, value OFF CON1_PIN23
PC03:    SPI0_CS    Pull-up level 1, value OFF CON1_PIN24
PC04:          -    Pull-up level 1, value OFF PU10K3.3V
PC05:          -          - level 1, value OFF
PC06:          -    Pull-up level 1, value OFF
PC07:          -    Pull-up level 1, value OFF PD10KGND
PC08:          -          - level 1, value OFF
PC09:          -          - level 1, value OFF
PC10:          -          - level 1, value OFF
PC11:          -          - level 1, value OFF
PC12:          -          - level 1, value OFF
PC13:          -          - level 1, value OFF
PC14:          -          - level 1, value OFF
PC15:          -          - level 1, value OFF
PC16:          -          - level 1, value OFF
PD00:          -          - level 1, value OFF
PD01:          -          - level 1, value OFF
PD02:          -          - level 1, value OFF
PD03:          -          - level 1, value OFF
PD04:          -          - level 1, value OFF
PD05:          -          - level 1, value OFF
PD06:          -          - level 1, value OFF
PD07:          -          - level 1, value OFF
PD08:          -          - level 1, value OFF
PD09:          -          - level 1, value OFF
PD10:          -          - level 1, value OFF
PD11:          -          - level 1, value OFF
PD12:          -          - level 1, value OFF
PD13:          -          - level 1, value OFF
PD14:          -          - level 1, value OFF
PD15:          -          - level 1, value OFF
PD16:          -          - level 1, value OFF
PD17:          -          - level 1, value OFF
PE00:          -          - level 1, value OFF
PE01:          -          - level 1, value OFF
PE02:          -          - level 1, value OFF
PE03:          -          - level 1, value OFF
PE04:          -          - level 1, value OFF
PE05:          -          - level 1, value OFF
PE06:          -          - level 1, value OFF
PE07:          -          - level 1, value OFF
PE08:          -          - level 1, value OFF
PE09:          -          - level 1, value OFF
PE10:          -          - level 1, value OFF
PE11:          -          - level 1, value OFF
PE12:   TWI2_SCK          - level 1, value OFF
PE13:   TWI2_SDA          - level 1, value OFF
PE14:          -          - level 1, value OFF
PE15:          -          - level 1, value OFF
PF00:    SDC0_D1    Pull-up level 2, value OFF µSD_PIN8
PF01:    SDC0_D0    Pull-up level 2, value OFF µSD_PIN7
PF02:   SDC0_CLK    Pull-up level 2, value OFF µSD_PIN5 SH33R
PF03:   SDC0_CMD    Pull-up level 2, value OFF µSD_PIN3 PU47K3.3V
PF04:    SDC0_D3    Pull-up level 2, value OFF µSD_PIN2
PF05:    SDC0_D2    Pull-up level 2, value OFF µSD_PIN1
PF06:      INPUT    Pull-up level 1, value OFF µSD_PIN9 PU47K3.3V
PG00:          -          - level 1, value OFF
PG01:          -          - level 1, value OFF
PG02:          -          - level 1, value OFF VDD_SYSY_3.3V !no resistor?
PG03:          -          - level 1, value OFF
PG04:          -          - level 1, value OFF
PG05:          -          - level 1, value OFF
PG06:   UART1_TX    Pull-up level 1, value OFF CON1_PIN8
PG07:   UART1_RX    Pull-up level 1, value OFF CON1_PIN10
PG08:          -          - level 1, value OFF CON1_PIN16
PG09:          -          - level 1, value OFF CON1_PIN18
PG10:          -          - level 1, value OFF
PG11:     OUTPUT          - level 1, value ON  CON1_PIN7
PG12:          -          - level 1, value OFF PU10K3.3,USB0-ID
PG13:          -          - level 1, value OFF
PL00:  S_TWI_SCK    Pull-up level 2, value OFF
PL01:  S_TWI_SDA    Pull-up level 2, value OFF
PL02:     OUTPUT          - level 1, value ON
PL03:          -          - level 1, value OFF PU10K3.3V,K1
PL04:          -          - level 1, value OFF PU10K3.3V,RECOVERY
PL05:     OUTPUT          - level 3, value OFF
PL06:     OUTPUT    Pull-up level 2, value OFF PU10K3.3,CPUX-VSET0 (VDD-CPUX=0?1.1V:1.3V)
PL07:          -          - level 1, value OFF
PL08:     OUTPUT          - level 3, value ON  PU10K3.3,PWR-STBY_ENABLE_HIGH
PL09:     OUTPUT          - level 3, value ON  PU10K3.3,PWR-DRAM_ENABLE_HIGH
PL10:     OUTPUT          - level 1, value ON  PU10K3.3,RED_LED