Standard usage

When using a VCI-AVALON component, you must explicitely define the three following Avalon parameters:

	address_width
	data_width
	burstcount_width

So you may factor out these parameters putting them at the end of the list of the VCI parameters as shown in the following example of a platform_desc file:

todo = Platform('caba', 'top.cpp',
				uses = [
	Uses('iss_wrapper', iss_t = 'common:nios2_fast'),
	Uses('vci_ram'),
	Uses('vci_multi_tty'),
	Uses('avalon_switch_fabric'),
	Uses('vci_avalon_target_wrapper'),
	Uses('vci_avalon_initiator_wrapper'),
	Uses('vci_xcache'),
	],
	cell_size = 4,
	plen_size = 8,
	addr_size = 32,
	rerror_size = 1,
	clen_size = 1,
	rflag_size = 1,
	srcid_size = 8,
	pktid_size = 1,
	trdid_size = 1,
	wrplen_size = 1,
	nb_master = 1,
	nb_slave = 2,
	address_width = 32, 
	data_width = 32, 
	burstcount_width = 8
)