
4.5 Timing Rule
Table 4.75 Timing specifications (2 of 3)
No. | Name | Standard | Timing specification |
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6 | Bus Settle Delay | 400 ns min. | Minimum wait period between the time a |
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| particular control signal condition changes and |
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| the time the bus condition is stabilized. |
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7 | Cable Skew | 10 ns max. | Maximum allowable difference in transmission |
| Delay |
| time over the interface cable between any two |
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| bus signals from any two SCSI devices. |
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8 | Data release | 400 ns max. | Maximum allowable period between the time an |
| Delay |
| I/O signal changes its status from false to true |
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| and the time the INIT stops driving data bus |
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| signals. |
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9 | Deskew Delay | 45 ns min. | Time for compensation for skew involved in bus |
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| signal transmission. |
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10 | Hold Time | 45 ns min. | In synchronous data transfer mode, the |
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| minimum time during which the transfer data on |
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| the DATA BUS from the leading edge of the |
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| REQ or ACK signal pulse must be maintained to |
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| compensate for the hold time in the SCSI device |
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| receiving data. |
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11 | Negation Period | 90 ns min. | In synchronous data transfer mode, the |
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| minimum time from the trailing edge of an REQ |
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| signal to the leading edge of the next REQ |
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| signal, or from the trailing edge of an ACK |
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| signal to the leading edge of the next ACK |
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| signal. |
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12 | 10 sec max. | Maximum time from when the TARG is turned | |
| Selection Time |
| on to the time the TARG can post the correct |
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| status and sense data for the TEST UNIT |
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| READY, INQUIRY or REQUEST SENSE |
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| command. |
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13 | Reset to | 250 ms max. | Maximum time from when the RESET condition |
| Selection Time |
| (hard RESET) is released to the time the TARG |
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| can post the correct status and sense data for the |
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| TEST UNIT READY, INQUIRY or REQUEST |
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| SENSE command. |
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14 | Reset Hold | 25µs min. | The minimum time during which the RST signal |
| Time |
| must be held true to create a RESET condition. |
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| A maximum time is not defined. |
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15 | Selection Abort | 200µs max. | In a SELECTION or RESELECTION phase, the |
| Time |
| maximum allowable period between the time the |
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| SCSI device recognizes itself as selected and the |
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| time it replies with a BSY signal. |
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