What the 60 ns access time means for your frame buffer
The TMS55166-70ADGH is a 256Kx16 Video DRAM with a 60 ns access time — the row-address strobe (RAS) to column-address strobe (CAS) delay determines how fast the memory can feed pixel data to the DAC. In a 1024x768 display at 60 Hz, the pixel clock is about 65 MHz, so each pixel window is roughly 15 ns; a 60 ns random access means the DRAM must be interleaved or burst-sequenced to keep the scan line filled without stalling the raster.