GENERAL DESCRIPTION
The two PAL blocks are essentially “PAL22V16” structures complete with product-term arrays and programmable macrocells. The switch matrix connects the PAL blocks to each other and to all input pins, providing a high degree of connectivity between the fully-connected PAL blocks. This allows designs to be placed and routed efficiently. The MACH110 macrocell provides either registered or combinatorial outputs with programmable polarity. If a registered configuration is chosen, the register can be configured as D-type or T-type to help reduce the number of product terms. The register type decision can be made by the designer or by the software. All macrocells can be connected to an I/O cell. If a buried macrocell is desired, the internal feedback path from the macrocell can be used, which frees up the I/O pin for use as an input. Publication# 14127 Rev. I Issue Date: May 1995 Amendment /0 AMD BLOCK DIAGRAM I/O0 – I/O15 I0 – I1, I3 – I4 16 16 I/O Cells 16 16 2 Macrocells...
Advanced Micro Devices
