Below is the Spansion IBIS file name reference for different OPN.

s34mS04g1_A_B_C_rD.ibs

A (Package Type): 
	
a = 63-ball VFBGA 11 x 9 mm package, 0.80 mm pitch (VBM063) (X8 ONFI/ LEGACY)
b = 63-ball VFBGA 11 x 9 mm package, 0.80 mm pitch (VBM063) (X16 ONFI)
c = 63-ball VFBGA 11 x 9 mm package, 0.80 mm pitch (VBM063) (X16 LEGACY)
t = 48 pin Thin Small Outline Package (TSOP 48) Standard Pinout (X8 ONFI/ LEGACY)
s = 48 pin Thin Small Outline Package (TSOP 48) Standard Pinout (X16 ONFI/ LEGACY)
k = KGD (Known Good Die)

B (Temperature Range):
	
i = Industrial (-30C to 85C)
v = Automotive In-Cabin (-40C to 105C)


C (VIO Voltage):

18 = (VIO = VCC = 1.65V to 1.95V, typ VIO = 1.8V)


D (revision number)



Example:

The IBIS file name 's34mS04g1_b_i_30_r1.ibs' is for s34mS04g1 in 
VFBGA 11x9 package (VBM063) for typical VIO of 1.8V, 
with industrial temperature and ibis model revision of 1.0.