DP8428

The DP8428 and DP8429 1M DRAM Controller/Drivers are designed to provide ``No-Waitstate'' CPU interface to Dynamic RAM arrays of up to 8 Mbytes and larger. The DP8428 and DP8429 are tailored for 32-bit and 16-bit system requirements, respectively. Both devices are fabricated using National's new oxide isolated Advanced Low power Schottky (ALS) process and use design techniques which enable them to significantly out-perform all other LSI or discrete alternatives in speed, level of integration, and power consumption.

Each device integrates the following critical 1M DRAM controller functions on a single monolithic device: ultra precise delay line; 9 bit refresh counter; fall-through row, column, and bank select input latches; Row/Column address muxing logic; on-board high capacitive-load RAS, CAS, Write Enable and Address output drivers; and, precise control signal timing for all the above.

In order to specify each device for ``true'' worst case operating conditions, all timing parameters are guaranteed while the chip is driving the capacitive load of 88 DRAMs including trace capacitance. The chip's delay timing logic makes use of a patented new delay line technique which keeps AC skew to g3 ns over the full VCC range of g10% and temperature range of b55ßC to a125ßC. The DP8428 and DP8429 guarantee a maximum RASIN to CASOUT delay of 80 ns or 70 ns even while driving an 8 Mbyte memory array with error correction check bits included. Two speed selected options of these devices are shown in the switching characteristics section of this document.