SPI pins on ATSAMD21GA chip

I understand that the I2C pins are mapped to PA22(SDA) and PA23(SCL) on the ATSAMD21GA chip. The UART pins are also as follow PA10(RX) and PA11(TX). What pins are MOSI, MISO, SCK and SS mapped to out of the box? The datasheets I have found so far does not help much in this regard. Also can I use this chip without connecting an external oscillator?

On the SAMD chip, UART, I2C, and SPI are all handled by "SERCOM" peripherals.
There are a total of 6, and at least theoretically, any of the 6 can do SPI.

On Arduino Zero and similar boards, it looks like the 6pin SPI connector is connected to SERCOM4 (PB10=MOSI, PB11=SCK, PA12=MISO)
Hardware SS is not used, but is accessible on Analog Pin 2 (PB09)

Thank you. That was helpful. Also I noticed D+ and D- which I think connects straight to a USB which in turn enables data or code to be loaded onto the board. Does that mean I won't need a USB-to-UART module connected to the RX and TX pins of the chip for that?

Using the hardware USB pin requires firmware on the chip. In the case of Arduino, both the bootloader and the sketches have USB code, but if you are starting from scratch, you may need an SWD debugger to load code.

westfw:
Using the hardware USB pin requires firmware on the chip. In the case of Arduino, both the bootloader and the sketches have USB code, but if you are starting from scratch, you may need an SWD debugger to load code.

Ok that makes sense now. I will just go ahead and use the hardware USB pins then since I am pressed for extra space in the board I am designing. Thank you very much for your help.

Does the ATSAMD21G need to be connected to an external 32kHz oscillator in order to use the RTC for date and calendar purposes?