4010 Auxiliary I/O Bus


In the RC4000UM it is stated that (section 4.1.1):
Parallel Port B pins PB2�PB7 can also be used as an auxiliary address bus. However, in the same document (Table 2) is also written that PB0 & PB1 can be used (Alternate use) as External I/O Address IA6 & IA7.

My question is: Can I use only PB2-PB7 as External I/O Address IA0-IA5 and use PB0 as SCLKB (for my SPI clock)? Or, if I use the auxiliary I/O bus it means all the pins of Parallel Port B will be part of the auxiliary I/O bus?


The description of the SPCR register clearly destinghuishes between B[7:0] and B[7:2]
Check register bits 4:2. You should use mode 011.
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