Seagate ST300MM0026 Savvio 10K.1 FC Product Manual - Page 68

9.5.4 Pin descriptions This section provides a pin-out of the FC-SCA and a description of the functions provided by the pins. Table 22: FC-SCA pin descriptions Pin Signal name Signal type Pin Signal name Signal type 1* -EN bypass port A Low Voltage TTL output 21 12 Volts charge 2* 12 Volts 22 Ground 3* 12 Volts 23 Ground 4* 12 Volts 24* +Port A_in Diff. PECL input pair 5* -Parallel ESI 6* Ground[1] 25* -Port A_in 26 Ground 7* Active LED out Open collector out 27* +Port B_in Diff. PECL input pair 8* Reserved 9* Start_1[2] 10* Start_2[2] TTL input TTL input 28* -Port B_in 29 Ground 30* +Port A_out Diff PECL output pair 11* -EN bypass port B Low Voltage TTL output 31* -Port A_out 12* SEL_6 TTL input/output 32 Ground 13* SEL_5 TTL input/output 33* +Port B_out Diff PECL output pair 14* SEL_4 TTL input 34* -Port B_out 15* SEL_3 TTL input/output 35 Ground 16* Fault LED out Open collector out 17* DEV_CTRL_CODE_2[2] TTL input 18* DEV_CTRL_CODE_1[2] TTL input 19* 5 Volts 36 SEL_2 TTL input/output 37 SEL_1 TTL input/output 38 SEL_0 TTL input/output 39 DEV_CTRL_CODE_0[2 TTL input 20* 5 Volts 40 5 Volts charge *Short pins in mating backpanel connector. [1] This pin may be connected to external logic to detect the presence of the drive. The drive connects this pin to the common ground. [2] Pins 9, 10, 17, 18, and 39 are option select pins and are tied high by the drive circuitry. The preferred electrical connection at the backplane is either open or grounded (open for the '1' setting, grounded for the '0' setting). Alternatively, these pins may be driven by a 3.3V logic device, pulled up to 3.3V through a pull-up resistor (recommended size of 10k ohm), or grounded through some other means. 62 Savvio FC Product Manual, Rev. D