问答 #32544 - Embedded Tri-mode Ethernet MAC Wrapper (Virtex-4) v4.7 - Implementation of MII interface might fail in MAP due to I/O banking rules
Embedded Tri-mode Ethernet MAC Wrapper (Virtex-4) v4.7 - Implementation of MII interface might fail in MAP due to I/O banking rules
| 问答编号# | 32544 |
| 型号 | IP-DS-Embedded Tri-Mode EMAC |
| 最后更新日期 | 2009-04-23 00:00:00.0 |
| 记录状态 | Active |
| 关键词 | place, MII_TX_CLK, IO Standards, 864 |
疑问描述
Keywords: place, MII_TX_CLK, IO Standards, 864
When a design with MII interface is implemented, intermittent failures occur in MAP with the following error:
"ERROR:Place:864 - Incompatible IOB's are locked to the same bank 2 Conflicting IO Standards are:
IO Standard 1: Name = LVCMOS25, VRR, VCCO = 2.50, TERM = NONE
List of locked IOB's: HOSTCLK
IO Standard 2: Name = LVTTL, VREF = NR, VCCO = 3.30, TERM = NONE
List of locked IOB's: MII_TX_CLK_1
These IO Standards are incompatible due to VCCO mismatch."
解决方案
To avoid this error, add the following constraints in the UCF:INST "MII_TX_CLK_1" LOC = "Bank4";
INST "MII_TX_CLK_0" LOC = "Bank4";
INST "MII_RX_CLK_1" LOC = "Bank4";
INST "MII_RX_CLK_0" LOC = "Bank4";