muxed
0		uart0_tx	spi0_sclk		uart2_tx	uart3_tx
1		uart0_rx	spi0_mosi		uart2_rx	uart3_rx
2		twi0_sda	spi0_ss   
3		twi0_scl	spi0_miso
8   sd0_clk   sd1_clk
9   sd0_cmd   sd1_cmd
10  sd0_d0    sd1_d0
11  sd0_d1    sd1_d1
12  sd0_d2    sd1_d2
13  sd0_d3    sd1_d3
dedicated
4		uart1_tx
5		uart1_rx
6		twi1_sda
7		twi1_scl
14   jtag0_tclk
15   jtag0_tdo
16  jtag0_tdi
17  jtag0_tms
18  jtag0_tdo