ZHCSCR3C October 2012 – August 2014 DS125BR111
PRODUCTION DATA.
PIN | I/O | DESCRIPTION | |
---|---|---|---|
NAME | NO. | ||
DIFFERENTIAL HIGH SPEED I/O | |||
INB+, INB- | 11, 12 | I | Inverting and non-inverting CML differential inputs to the equalizer. On-chip 50 Ω termination resistor connects INB+ to VDD and INB- to VDD when enabled by RXDET control logic. AC coupling required on high-speed I/O |
OUTB+, OUTB- | 20, 19 | O | Inverting and non-inverting 50 Ω driver outputs. Compatible with AC coupled CML inputs. AC coupling required on high-speed I/O |
INA+, INA- | 24, 23 | I | Inverting and non-inverting CML differential inputs to the equalizer. On-chip 50 Ω termination resistor connects INA+ to VDD and INA- to VDD when enabled by RXDET control logic. AC coupling required on high-speed I/O |
OUTA+, OUTA- | 7, 8 | O | Inverting and non-inverting 50 Ω driver outputs. Compatible with AC coupled CML inputs. AC coupling required on high-speed I/O |
CONTROL PINS — SHARED (LVCMOS) | |||
ENSMB | 3 | I, 4-LEVEL, LVCMOS |
System Management Bus (SMBus) enable Pin Tie 1 kΩ to VDD = Register Access SMBus Slave mode FLOAT = Read External EEPROM (Master SMBus Mode) Tie 1 kΩ to GND = Pin Mode |
ENSMB = Float or 1 (SMBus MODEs) | |||
SCL | 5 | I, LVCMOS, O, OPEN Drain |
ENSMB Master or Slave mode SMBus clock input Pin is enabled (slave mode). Clock output when loading EEPROM configuration (master mode). |
SDA | 4 | I, LVCMOS, O, OPEN Drain |
ENSMB Master or Slave mode The SMBus bidirectional SDA Pin is enabled. Data input or open drain output. External pull-up required as per SMBus protocol (typically in the 2 kΩ to 5 kΩ range). This pin is 3.3 V-tolerant. |
AD0-AD3 | 10, 9, 2, 1 | I, LVCMOS | ENSMB Master or Slave mode SMBus Slave Address Inputs. In SMBus mode, these Pins are the user set SMBus slave address inputs. |
READEN | 17 | I, LVCMOS | ENSMB = Float: When using an External EEPROM, a logic low on this pin starts the load from the external EEPROM ENSMB = 1: When using SMBus Slave Mode the VOD_SEL/READEN pin must be tied Low for the AD[3:0] to be active. If this pin is tied High or Floated an address of 0xB0 will be used for the DS125BR111. |
DONE | 18 | O, LVCMOS | When using an External EEPROM (ENSMB = Float), Valid Register Load Status Output HIGH = External EEPROM load failed or incomplete LOW = External EEPROM load passed |
ENSMB = 0 (PIN MODE) | |||
EQA0 EQB0 |
10 1 |
I, 4-LEVEL, LVCMOS |
EQA0 and EQB0 control the level of equalization of the A/B directions. The Pins are defined as EQx0 only when ENSMB is de-asserted (low). When ENSMB goes high the SMBus registers provide independent control of each channel. See Table 4. |
EQA1 EQB1 |
9 2 |
I, 4-LEVEL, LVCMOS |
EQA1 and EQB1 are not used in the DS125BR111 design. These pins should always be tied to GND. |
VODA_DB | 4 | I, 4-LEVEL, LVCMOS |
VODA_DB controls the CHA output amplitude dynamic range, for SAS and PCIe applications it should be held Low. The Pin is defined as VODA_DB only when ENSMB is de-asserted (low). When ENSMB goes high the SMBus registers provide control of each channel, pin 4 is converted to SDA. See Table 5. |
VODB_DB | 5 | I, 4-LEVEL, LVCMOS |
VODB_DB controls the CHB output amplitude dynamic range, for SAS and PCIe applications it should be held Low. The Pin is defined as VODB_DB only when ENSMB is de-asserted (low). When ENSMB goes high the SMBus registers provide control of each channel, pin 5 is converted to SCL. See Table 5. |
SD_TH | 14 | I, 4-LEVEL, LVCMOS |
Controls the internal Signal Detect Threshold. This detection threshold is for system debug only and does not control the high speed datapath. See Table 3. |
VOD_SEL | 17 | I, 4-LEVEL, LVCMOS |
VOD_SEL controls the low frequency ratio of input voltage to output voltage amplitude. See Table 5. |
RXDET | 18 | I, 4-LEVEL, LVCMOS |
The RXDET Pin controls the receiver detect function. Depending on the input level, a 50 Ω or > 50 kΩ termination to the power rail is enabled. In a SAS/SATA system RXDET should be set to a Logic "1" state to keep the termination always enabled. The RXDET pin only controls the RXDET function in PIN MODE. PCIe applications which require SMBus Mode functionality must utilize a specific register write sequence documented in PCIe Applications . If this sequence is not utilized, SMBus configuration modes will default the input terminations to active (50 Ω). See Table 2 . |
CONTROL PINS — BOTH PIN AND SMBus MODES (LVCMOS) | |||
RES | 13 | I, 4-LEVEL, LVCMOS |
Reserved: This input must be left Floating. |
VDD_SEL | 16 | I, FLOAT | Controls the internal regulator Float = 2.5 V mode Tie GND = 3.3 V mode |
PWDN | 6 | I, LVCMOS | Tie High = Low power - power down Tie GND = Normal Operation See Table 2. |
POWER (See Figure 11) | |||
VIN | 15 | Power | In 3.3 V mode, feed 3.3 V to VIN In 2.5 V mode, leave floating. |
VDD | 21, 22 | Power | Power supply pins CML/analog 2.5 V mode, connect to 2.5 V 3.3 V mode, decouple each VDD pin with 0.22 µF cap to GND |
GND | DAP | Power | Ground pad (DAP - die attach pad). |