From 6753cb705e726becc433ee39238ca00a5b929fe4 Mon Sep 17 00:00:00 2001 From: Andreas Hansson Date: Fri, 9 May 2014 18:58:48 -0400 Subject: mem: Add tRTP to the DRAM controller This patch adds the tRTP timing constraint, governing the minimum time between a read command and a precharge. Default values are provided for the existing DRAM types. --- src/mem/dram_ctrl.cc | 17 +++++++++-------- 1 file changed, 9 insertions(+), 8 deletions(-) (limited to 'src/mem/dram_ctrl.cc') diff --git a/src/mem/dram_ctrl.cc b/src/mem/dram_ctrl.cc index dd4b254ee..19a03b834 100644 --- a/src/mem/dram_ctrl.cc +++ b/src/mem/dram_ctrl.cc @@ -76,7 +76,7 @@ DRAMCtrl::DRAMCtrl(const DRAMCtrlParams* p) : writesThisTime(0), readsThisTime(0), tWTR(p->tWTR), tRTW(p->tRTW), tBURST(p->tBURST), tRCD(p->tRCD), tCL(p->tCL), tRP(p->tRP), tRAS(p->tRAS), tWR(p->tWR), - tRFC(p->tRFC), tREFI(p->tREFI), tRRD(p->tRRD), + tRTP(p->tRTP), tRFC(p->tRFC), tREFI(p->tREFI), tRRD(p->tRRD), tXAW(p->tXAW), activationLimit(p->activation_limit), memSchedPolicy(p->mem_sched_policy), addrMapping(p->addr_mapping), pageMgmt(p->page_policy), @@ -560,9 +560,10 @@ DRAMCtrl::printParams() const "tWTR %d ticks\n" \ "tRTW %d ticks\n" \ "tWR %d ticks\n" \ + "tRTP %d ticks\n" \ "tXAW (%d) %d ticks\n", name(), tRCD, tCL, tRP, tBURST, tRFC, tREFI, tWTR, - tRTW, tWR, activationLimit, tXAW); + tRTW, tWR, tRTP, activationLimit, tXAW); } void @@ -993,12 +994,12 @@ DRAMCtrl::doDRAMAccess(DRAMPacket* dram_pkt) // read/write (add a max with tCCD here) bank.colAllowedAt = cmd_at + tBURST; - // If this is a write, we also need to respect the write - // recovery time before a precharge - if (!dram_pkt->isRead) { - bank.preAllowedAt = std::max(bank.preAllowedAt, - dram_pkt->readyTime + tWR); - } + // If this is a write, we also need to respect the write recovery + // time before a precharge, in the case of a read, respect the + // read to precharge constraint + bank.preAllowedAt = std::max(bank.preAllowedAt, + dram_pkt->isRead ? cmd_at + tRTP : + dram_pkt->readyTime + tWR); // increment the bytes accessed and the accesses per row bank.bytesAccessed += burstSize; -- cgit v1.2.3