Adaptec 1737100 Programmer Manual - Page 115

Register Descriptions Completion Queue Registers Note: All completion queues have a fixed size of 1KByte entries. CompletionQueueHighAddr Register Type: R/W Internal Registers Subgroup: Ethernet Functional Registers Byte Address: B4h - B7h Table 7-55. CompQueueHighAddress Register Reset Bit(s) rw Value Description/Function 31:0 r/w x CompQueueHighAddr[31:0]: Upper 32-bits of address of all the completion queues. TxCompletionQueueCtrl Type: R/W Internal Registers Subgroup: Ethernet Functional Registers Byte Address: B8 - BBh Table 7-56. TxCompletionQueueCtrl Register Reset Bit(s) rw Value Description/Function 31:8 r/w 7 r/w x TxCompletionBaseAddress[31:8]: This field contains the starting address of the queue in host memory. It is written by the host driver during initialization and read by the AIC-6915. The amount of host memory allocated for the completion queue is either 4-KBytes, 8KBytes, or 16-KBytes (programmable by bits 5:4, RXCOMPLETIONQ1TYPE). The start address must be aligned to a 256byte boundary. The total number of completion descriptor entries in the queue is fixed at 1024. 0 TxCompletion64bitAddress: This bit indicates if the transmit Completion Queue is located in 64-bit address space, If so, the AIC-6915 PCI Master must use 64-bit addressing mode to access the queue. 6 r/w 0 TxCompletionProducerWe: When this bit is set, the software driver is able to write the transmit completion queue producer index. Otherwise, writes to the index are disabled. When the bit is cleared the queue is disabled and the AIC-6915 cannot add entries to the queue. 5 r/w 0 TxCompletionSize: When this bit is set, each transmit completion descriptor size is 8-bytes, which makes the entire completion queue 8-KBytes. When cleared, each transmit completion descriptor size is 4-bytes, which makes the entire completion queue 4-KBytes. 7-43