Once a change in operating mode occurs, the initiator SCRIPTS should start with a Set Initiator instruction or the target SCRIPTS should start with a Set Target instruction. The Selection and Reselection Enable bits (SCSI Chip ID (SCID) bits 5 and 6, respectively) should both be asserted so that the LSI53C810A may respond as an initiator or as a target. If only selection is enabled, the LSI53C810A cannot be reselected as an initiator. There are also status and interrupt bits in the SCSI Interrupt Status Zero (SIST0) and SCSI Interrupt Enable Zero (SIEN0) registers, respectively, indicating that the LSI53C810A has been selected (bit 5) or reselected (bit 4).

Figure 2.3 Active or Regulated Termination

2.85V

 

C1

C2

 

UC5601QP

 

2

REG_OUT

TERML1 20

TERML2 21

 

 

 

 

TERML3 22

 

 

TERML4 23

 

 

TERML5 24

 

 

TERML6 25

 

 

TERML7 26

 

 

TERML8 27

 

 

TERML9 28

 

 

TERML10

3

 

 

TERML11

4

 

 

TERML12

5

 

 

TERML13

6

 

 

TERML14

7

19 DISCONNECT

TERML15

8

TERML16

9

 

 

TERML17

10

TERML18

11

SD0 (J1.2) SD1 (J1.4) SD2 (J1.6) SD3 (J1.8)

SD4 (J1.10) SD5 (J1.12) SD6 (J1.14) SD7 (J1.16) SD8 (J1.18)

ATN (J1.32) BSY (J1.36) ACK (J1.38) RST (J1.40) MSG (J1.42) SEL (J1.44) C/D (J1.46)

REQ (J1.48) I/O (J1.50)

Note:

1.C1 - 10 μF SMT

2.C2 - 0.1 μF SMT

3.J1 - 68-pin, high density “P” connector

2-12

Functional Description

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Image 32
LSI 53C810A technical manual Active or Regulated Termination