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AN83REV1
CS8900 Technical Reference Manual
Figure 2.3.2 PAL Program
;----------------------------------- Boolean Equation Segment ------
EQUATIONS
; Serial shift register
; When CS_EL_b is inactive (1), no change
; When CS_EL_b is active (0), shift in data
Q20 := (Q20 * CS_EL_b) + (/CS_EL_b * SDATA)
Q21 := (Q21 * CS_EL_b) + (/CS_EL_b * Q20)
Q22 := (Q22 * CS_EL_b) + (/CS_EL_b * Q21)
Q23 := (Q23 * CS_EL_b) + (/CS_EL_b * Q22)
; Decode logic
EQUALL = (Q20:*:LA20) * (Q21:*:LA21) ; :*: -> Exclusive NOR operator
EQUALH = (Q22:*:LA22) * (Q23:*:LA23)
CHIPSEL_b = RESET ; Get set at RESET
+ /ADD_VALID ; Remain set till address is valid
+ (/ALE * CHIPSEL_b) ; Do not change when ALE is LOW
+ (ALE * /(EQUALL * EQUALH)) ; Clear during ALE if address matches
; When ALE is active; CS_b goes active if EQUAL[1:2] are true
; When ALE is inactive; previous state of CS_b is latched.
Summary of Contents for CRYSTAL LAN CS890
Page 26: ...26 AN83REV1 CS8900 Technical Reference Manual Figure 2 2 9 CRD8900 Top Side Routing ...
Page 27: ...AN83REV1 27 CS8900 Technical Reference Manual Figure 2 2 10 CRD8900 Bottom Side Routing ...
Page 41: ...AN83REV1 41 CS8900 Technical Reference Manual Figure 2 4 7 5V Plane of four layer board ...
Page 42: ...42 AN83REV1 CS8900 Technical Reference Manual Figure 2 4 8 Ground Plane of four layer board ...