The HM538253B/HM538254B is a 2-Mbit multiport video RAM equipped with a 256-kword x 8-bit dynamic RAM and a 512-word x 8-bit SAM (full-sized SAM). Its RAM and SAM operate independently and asynchronously. The HM538253B/HM538254B is upwardly compatible with the HM534253B/HM538123B except that the pseudo-write-transfer cycle is replaced with masked-write-transfer cycle, which has been approved by JEDEC. Furthermore, several new features have been added to the HM538253B/HM538254B which do not conflict with the conventional features. The stopping column feature realizes allows greater flexibility for split SAM register lengths. Persistent mask is also installed according to the TMS34020 features. The HM538254B has Hyper page mode which enables fast page cycle.