Device control register

• The ISA PNP specification divides the registers of a device in two categories: control registers and configuration registers. One of the device control registers defined by ISA PNP is the Activate register, which turns the card on or off.
• The Device Control Register is also the name of a specific register in the PCI Express architecture. It has fields that control what is the maximum read request size that the device can make.
• Device Control Register is also the name of an IBM proprietary bus. Its stated design goal is to "transfer data between a DCR master, typically a CPU’s general purpose registers, and the DCR slave logic’s device control registers". For example, the IBM MultiProcessor Interrupt Controller is connected up to four processors via a shared DCR bus, and in turn the MPIC handles up to 128 interrupt sources.