参数资料
型号: FR3-16M
厂商: TechTools
文件页数: 25/38页
文件大小: 0K
描述: EMULATOR FLASH FLEXROM III 16MEG
标准包装: 1
系列: FlexROM™ III
类型: 存储器
适用于相关产品: 外部 FLASH、EPROM 或 SRAM 设备
所含物品: 需要 FR3 FlexROM III 仿真器、缆线(菊花链、LPT、迷你型夹和目标)、软件、有源缆线模块
其它名称: FR316M
Filtering
FlexROM III provides the ability to filter noise out of the target’s control signals before using them to
control the SRAMs or to detect the end of valid cycles (for arbitration, snap-shot & trigger). Any noise on a
control signal while it is active can corrupt a target write or cut into the read margins. Filtering out this
noise greatly improves emulator performance in noisy environments.
The up side to filtering is a more robust emulator. The trade-off (there’s ALWAYS a trade-off) is that the
greater the filtering, the longer it takes to determine that the cycle really ended. For example, if we are
filtering out pulses shorter than 20ns, the true end of cycle must obviously last somewhat longer than 20ns
or we will filter it out as noise. Even if end-of-cycle gets filtered out, the target can usually continue to
function properly. The end-of-cycle detection is used to update our SNAP-SHOT register, the trigger
circuit and to terminate target write cycles.
The default settings enable the control line filters and sets them to minimum filtering. This is a reasonable
default that allows full speed access on most targets. In fact, most targets could increase the filtering to
MAX and still meet timing.
The only time you may have to turn off filtering is if:
-
-
-
The target does writes to the emulator OR you are doing READY mode arbitrated accesses.
AND the target has very short cycle recovery times
AND the target has fast access time (45ns) requirements
If you are not doing arbitrated accesses to the emulator and the target does not write to the emulator, you
can usually add as much filtering as you want. In this situation, too much filtering on a target with short
recovery times would result in the SNAP-SHOT & trigger circuits failing to update, but the target would
function correctly as long the LATCHING options (see next section) are left at their defaults.
Latching
FlexROM III always latches the address lines during a target write. This enables it to enforce proper
address hold times to the SRAM despite varying path delays or sloppy target timing. By default, they are
only held stable while the target CS and WT signals are BOTH active.
In some cases, it might be desirable to latch the addresses on reads as well as writes or to latch them as soon
as CS goes active. To avoid latching noise, it is sometimes desirable to delay latching until some time after
the control signal. Most system noise occurs immediately after control signal transitions. Delaying the
actual freezing allows the signals to settle.
FlexROM III gives you the ability to select the source that triggers the latch and how long AFTER the
trigger it will wait before actually freezing the signals.
The latching options and possible reasons you would want to use them are listed below.
FlexROM III User’s Manual
23
Copyright ? 2001, TechTools
相关PDF资料
PDF描述
TC1270AMVRCTR IC RESET MONITOR 4.38V SOT143-4
FR3-8M EMULATOR FLASH FLEXROM III 8MEG
VE-B7W-EY-F4 CONVERTER MOD DC/DC 5.5V 50W
TC1270AMVCTTR IC RESET MONITOR 4.38V SOT23A-5
VE-B7W-EY-F3 CONVERTER MOD DC/DC 5.5V 50W
相关代理商/技术参数
参数描述
FR3-1M 功能描述:EMULATOR FLASH FLEXROM III 1MEG RoHS:否 类别:编程器,开发系统 >> 过时/停产零件编号 系列:FlexROM™ III 标准包装:1 系列:- 传感器类型:CMOS 成像,彩色(RGB) 传感范围:WVGA 接口:I²C 灵敏度:60 fps 电源电压:5.7 V ~ 6.3 V 嵌入式:否 已供物品:成像器板 已用 IC / 零件:KAC-00401 相关产品:4H2099-ND - SENSOR IMAGE WVGA COLOR 48-PQFP4H2094-ND - SENSOR IMAGE WVGA MONO 48-PQFP
FR-31SERIES 制造商:未知厂家 制造商全称:未知厂家 功能描述:surface mount circulator
FR31-SERIES 制造商:未知厂家 制造商全称:未知厂家 功能描述:surface mount circulator
FR32 制造商:MA-COM 制造商全称:M/A-COM Technology Solutions, Inc. 功能描述:Single Junction Surface Mount Isolator 800MHz, 900MHz, 1800MHz, 1900MHz, 2100MHz
FR-32 制造商:未知厂家 制造商全称:未知厂家 功能描述:surface mount isolator