AN11001 CBTL02042A switching application for mSATA and PCI Express Mini-Card Rev. 1 — 7 March 2011 Application note Document information Info Content Keywords CBTL02042, CBTL02043A, CBTL04082A, CBTL04083A, PCI Express, Mini-Card, SATA, SATA-IO, mSATA Abstract mSATA and PCI Express Mini-Card are sharing the same physical connector type with minor pin definition modification. Automatic card detection and signal multiplexing function between SATA interface and PCI Express interface can be implemented using CBTL02042A. PCB design should account for the insertion loss by the multiplexer and reduce the trace length accordingly. AN11001 NXP Semiconductors CBTL02042A switching application for mSATA, PCIe Mini-Card Revision history Rev Date Description v.1 20110307 application note; initial release Contact information For more information, please visit: http://www.nxp.com For sales office addresses, please send an email to: [email protected] AN11001 Application note All information provided in this document is subject to legal disclaimers. Rev. 1 — 7 March 2011 © NXP B.V. 2011. All rights reserved. 2 of 17 AN11001 NXP Semiconductors CBTL02042A switching application for mSATA, PCIe Mini-Card 1. Introduction NXP’s CBTL02042A (shown in Figure 1) is a 3.3 V, 2-to-1 multiplexer/de-multiplexer specially designed for switching between PCIe Gen 2 (up to 5 Gbit/s) and SATA Gen 2 (up to 3 Gbit/s) signals, with features such as low insertion loss (1.2 dB at 2.5 GHz), low crosstalk (30 dB at 2.5 GHz), and low operating power consumption (< 1 mA). A motherboard manufacturer can use CBTL02042A for multiplexing between PCIe Gen 2 and SATA signals connecting to an mSATA/Mini-Card socket. This document discusses system level design guidelines and considerations while using CBTL02042A in a Mini-Card/mSATA sub-system. CBTL02042A A0_P B0_P A0_N B0_N A1_P B1_P A1_N B1_N C0_P C0_N C1_P C1_N SEL XSD Fig 1. 002aaf875 CBTL02042A functional block diagram 2. Mini-Card and mSATA applications Both mSATA (from SATA-IO) and Mini-Card (from PCI SIG) share the same form-factor and similar electrical pinout assignments on their connectors. Mini-Cards are PCI Express (or PCIe)-based devices, and PCIe interface signals are accessible on the connectors. An mSATA device’s connector replaces PCIe interface signals with SATA interface, but with power and ground signals assigned to the same connector pins as Mini-Card’s. There was no clear mechanism to distinguish if a mSATA drive or a Mini-Card device is plugged into the socket until recently that SATA-IO issued an ECN change (ECN #45) to re-define pin 43 on mSATA connector as ‘no connect’ instead of ‘return current path’ (or GND). AN11001 Application note Table 1. mSATA and Mini-Card pin assignments Pin mSATA Description Mini-Card P1 reserved no connect WAKE# P2 +3.3 V 3.3 V source +3.3 Vaux P3 reserved no connect COEX1 P4 GND return current path GND P5 reserved no connect COEX2 P6 +1.5 V 1.5 V source +1.5 V P7 reserved no connect CLKREQ# All information provided in this document is subject to legal disclaimers. Rev. 1 — 7 March 2011 © NXP B.V. 2011. All rights reserved. 3 of 17 AN11001 NXP Semiconductors CBTL02042A switching application for mSATA, PCIe Mini-Card AN11001 Application note Table 1. mSATA and Mini-Card pin assignments …continued Pin mSATA Description Mini-Card P8 reserved no connect UIM_PWR P9 GND return current path GND P10 reserved no connect UIM_DATA P11 reserved no connect REFCLK P12 reserved no connect UIM_CLK P13 reserved no connect REFCLK+ P14 reserved no connect UIM_RESET P15 GND return current path GND P16 reserved no connect UIM_VPP P17 reserved no connect reserved (UIM_C8) P18 GND return current path GND P19 reserved no connect reserved (UIM_C4) P20 reserved no connect W_DISABLE# P21 GND return current path GND P22 reserved no connect PERST# P23 +B host receiver differential signal pair PERn0 P24 +3.3 V 3.3 V source +3.3 Vaux P25 B host receiver differential signal pair PERp0 P26 GND return current path GND P27 GND return current path GND P28 +1.5 V 1.5 V source +1.5 V P29 GND return current path GND P30 Two Wire Interface two-wire interface clock SMB_CLK P31 A host transmitter differential signal pair PETn0 P32 Two Wire Interface two-wire interface data SMB_DATA P33 +A host transmitter differential signal pair PETp0 P34 GND return current path GND P35 GND return current path GND P36 reserved no connect USB_D P37 GND return current path GND P38 reserved no connect USB_D+ P39 +3.3 V 3.3 V source +3.3 Vaux P40 GND return current path GND P41 +3.3 V 3.3 V source +3.3 Vaux P42 reserved no connect LED_WWAN# P43 no connect no connect indicates mSATA use GND P44 reserved no connect LED_WLAN# P45 Vendor vendor specific / manufacturing pin reserved P46 reserved no connect LED_WPAN# P47 Vendor vendor specific / manufacturing pin reserved P48 +1.5 V 1.5 V source +1.5 V All information provided in this document is subject to legal disclaimers. Rev. 1 — 7 March 2011 © NXP B.V. 2011. All rights reserved. 4 of 17 AN11001 NXP Semiconductors CBTL02042A switching application for mSATA, PCIe Mini-Card Table 1. mSATA and Mini-Card pin assignments …continued Pin mSATA Description Mini-Card P49 DA/DSS Device Activity signal / Disable Staggered Spin-up reserved P50 GND return current path GND P51 Presence Detection shall be pulled to GND by device reserved P52 +3.3 V 3.3 V source +3.3 Vaux This ECN change enables a card-type detection mechanism by adding a pull-up resistor on pin 43 on the socket. When an mSATA drive is inserted, its pin 43 is ‘no connect’, and the respective pin on the socket is being pulled-up to logic 1. When a Mini-Card device is inserted, its pin 43 forces the respective pin on the socket to ground, or logic 0. The host processor (or CPU) can utilize this information to enable either a SATA or a PCIe host controller on a notebook motherboard. Figure 2 illustrates a typical block diagram of Mini-Card/mSATA sub-system implementation using CBTL02042A. Table 2. Pin 43 statuses while different devices inserted Device inserted PCIe Mini-Card mSATA drive Pin 43 status logic 0 logic 1 RX TX SEL CBTL 02042A SATA CONTROLLER TX Mini-Card/mSATA CONNECTOR PCIe CONTROLLER Mini-Card mSATA RX 019aaa989 Fig 2. AN11001 Application note Mini-Card/mSATA sub-system block diagram All information provided in this document is subject to legal disclaimers. Rev. 1 — 7 March 2011 © NXP B.V. 2011. All rights reserved. 5 of 17 AN11001 NXP Semiconductors CBTL02042A switching application for mSATA, PCIe Mini-Card 3. Switching circuit schematic Figure 3 illustrates circuit schematics of Mini-Card/mSATA connector socket, CBTL02042A, and connections to PCIe and SATA host controllers (shown as transmitter and receiver symbols). Pins 3, 4, 7, and 8 (connector-side port) of CBTL02042A are differential pair signals connecting to the connector socket. Based on the logic level of the SEL signal, the port on the connector side will connect either to pins 19, 18, 17, and 16 (SEL_0_Port) when SEL = 0, or to pins 15, 14, 13, and 12 (SEL_1_Port) when SEL = 1. Information in Table 2 institutes the circuit diagram such that SEL_0_Port should be connected to a PCIe host controller, and SEL_1_Port should be connected to a SATA host controller. CARD_DET to GPIO 10 nF Fig 3. B0_P 19 3 A0_P B0_N 18 4 A0_N B1_P 17 5 VSS B1_N 16 6 VDD VDD VDD C0_P 15 7 A1_P C0_N 14 8 A1_N C1_P 13 9 SEL C1_N 12 R1 33 kΩ VDD PERn0 PERp0 100 nF 100 nF 10 nF PETn0 PETp0 +B 10 nF −B 10 nF −A 10 nF +A to PCIe host controller 10 nF 2 XSD PCIe host controller to SATA host controller R2 33 kΩ SATA host controller 11 VSS PIN P21 P22 P23 P24 P25 P26 P27 P28 P29 P30 P31 P32 P33 P34 P35 P36 P37 P38 P39 P40 P41 P42 P43 P44 10 VDD MiniCard/mSATA connector socket VDD 1 VDD VSS 20 VDD 10 nF SEL to GPIO 019aab324 Schematics of CBTL02042A connection to Mini-Card/mSATA connector socket In Figure 3 above, the XSD pin (pin 2) of CBTL02042A is connected to pin 21 of the connector with a 33 k pull-up resistor. The purpose of this pin is to detect if there is a Mini-Card or an mSATA device inserted to the connector, similar to a card detect signal found in most card-based sub-systems. Pin 21 is chosen such that this pin is grounded on the device side. When there is no device inserted in the connector socket, the state of XSD pin (and ‘CARD_DET’ signal) is HIGH. This signal can be used to notify the chip set that no device is inserted, PCIe and mSATA functions for this Mini-Card/mSATA sub-system can be disabled, and CBTL02042A is placed under Shutdown mode to conserve power. On the contrary, when a device is inserted, ‘CARD_DET’ signal is being grounded by the device, and logic level of zero forces CBTL02042A to resume in normal operating mode. The schematics might be modified to connect ‘CARD_DET’ signal to any other pin that is being assigned as ground on the connector. AN11001 Application note All information provided in this document is subject to legal disclaimers. Rev. 1 — 7 March 2011 © NXP B.V. 2011. All rights reserved. 6 of 17 AN11001 NXP Semiconductors CBTL02042A switching application for mSATA, PCIe Mini-Card 4. Mini-Card/mSATA routing guidelines (summary) High-speed signals on Mini-Card and mSATA devices are listed in Table 3. PCB design must follow general guidelines of these high-speed signals as suggested by the chip set manufacturer. This section briefly discusses these guidelines. Table 3. Mini-Card/mSATA high speed signals Card type Signal name Description Mini-Card PETp0, PETn0 PCI Express Tx differential pair mSATA PERp0, PERn0 PCI Express Rx differential pair +A, A SATA Tx differential pair +B, B SATA Rx differential pair 4.1 PCI Express routing guideline (without multiplexer in topology) The Mini-Card topology supports up to four vias for each transmit or receive differential signal, with maximum of 10 inches (25.4 cm) of trace length from chip set pin to the Mini-Card connector. Maximum trace length includes all routing sections, including breakout region from the chip set, main route, and breakout region to the connector. Length mismatch within the differential pair should not exceed 5 mils. If signals can be routed without switching to a different layer, less vias will be used, and impedance change of the differential pairs can be avoided as well. Figure 4 illustrates the required routing for PCI Express differential signals from chip set to a Mini-Card connector. The PCIe interface is an x1 link and can be routed to different devices at varied locations of the board, it is practical to route TX signals and RX signals of each link next to each other on the same PCB layer. • Total trace length from chip set pin to Mini-Card connector should not exceed 10 inches (25.4 cm). If at all possible, it is recommended to route the signals on the top layer with no vias. • Maximum main route length should not exceed 8 inches (20.32 cm), and should include maximum of one via in the main route region for each signal. Route the main route signals on the PCB top layer if possible so that the trace can be connected to AC coupling capacitors (also located on the top layer) directly. • Trace length in the breakout area near chip set side and connector side should be limited to be less than 0.5 inch (1.27 cm). Similar to main route, maximum of one via in each breakout region is allowed. • AC coupling capacitors with values of between 75 nF and 200 nF for the transmit signals should be located near the connector side. RX signals on the motherboard sides do not require AC coupling capacitors since those capacitors are located on the device side. AN11001 Application note All information provided in this document is subject to legal disclaimers. Rev. 1 — 7 March 2011 © NXP B.V. 2011. All rights reserved. 7 of 17 AN11001 NXP Semiconductors CBTL02042A switching application for mSATA, PCIe Mini-Card maximum 25.4 cm (10 inches) BREAKOUT maximum 500 mil (0.5 inch; 1.27 cm) MAIN ROUTE BREAKOUT maximum 20.32 cm (8 inches) 500 mil MiniCard connector PETp0 72 nF to 200 nF PETn0 PERp0 PERn0 019aaa990 Locations of vias and routing layer changes shown in this figure are for illustration purposes only. PCB layout design should minimize the use of vias and layer changes during routing process as discussed in the general guideline. Fig 4. Mini-Card topology example 4.2 SATA routing guideline (without multiplexer in topology) General routing and placement guidelines for SATA signals are: • SATA signals should be referenced to internal ground plane. If it is necessary to change reference to power plane (such that SATA signals are routed on the bottom layer, which is referenced to power or VCC plane on PCB), capacitors with low ESR values should be placed at locations where the SATA signals are changing layers, and between power and ground planes to minimize the negative impact of EMI and signal integrity performance caused by reference plane change. These capacitors provide a high frequency current return path between different reference planes, and minimize the impedance discontinuity and current loop area that crossing different reference planes created. • Route differential traces over a continuous ground planes with no interruptions. Routing across a split ground plane (which contains anti-etch) should be avoided. • If a layer change is absolutely necessary, make sure the trace matching for either transmit or receive pair occurs within the same layer. It is also recommended to not to use vias whenever possible. A maximum of four vias are allowed on the path, inclusive of the though-hole via of the external connector. • Route TX and RX pairs close to each other and on the same PCB layer with minimum mismatch of trace length within the pair. Trace length matching should be within the differential pair for each segment between points of discontinuity. Points of discontinuity could be vias, capacitor pads, or connector pins. Total length mismatch should not exceed 20 mils. It is not necessary to match the trace length of TX and RX pairs since they operate independently. • Do not route SATA traces under power connectors, other interface connectors, crystals, oscillators, clock synthesizers, or magnetic devices that use and/or duplicate clocks. • Route SATA signal traces away from etching areas, including pads, vias, and other signal traces. Keep minimum keep-out distance of 20 mils whenever possible. AN11001 Application note All information provided in this document is subject to legal disclaimers. Rev. 1 — 7 March 2011 © NXP B.V. 2011. All rights reserved. 8 of 17 AN11001 NXP Semiconductors CBTL02042A switching application for mSATA, PCIe Mini-Card • AC coupling capacitors should be placed close to the connector for optimal signal quality. Capacitors must be of type X7R with values of 10 nF 15 % and body size 0402. • Maximum of 6 inches (15.24 cm) trace length from host controller to SATA connector is strongly suggested. 4.3 Topology with CBTL02042A as a switch for Mini-Card/mSATA CBTL02042A, like other high-speed switches, introduces certain amount of signal loss at different frequencies. Without any switch on a PCB trace, the PCB trace itself introduces some loss as well. Although the CBTL02042A can operate up to 7 Gbit/s, this particular application mandates the operating speed of mSATA up to 3 Gbit/s (SATA Gen 2), and PCIe on the Mini-Card up to 2.7 Gbit/s (PCIe Gen1). Hence, the critical signal frequency we will be focusing on is 1.5 GHz. Typically, a signal loss of 0.25 dB exists for every 1 inch (2.54 cm) of PCB trace on FR4 material at frequency of 1.5 GHz. At this frequency, CBTL02042A exhibits signal loss of less than 1 dB, or translating to 3 inches (7.62 cm) to 4 inches (10.16 cm) of PCB trace. Keep this in mind, traces length of PCIe and SATA signals will need to be reduced by 3 inches (7.62 cm) to 4 inches (10.16 cm) when CBTL02042A is used to select either PCIe or SATA signals. Effectively, with CBTL02042A, the maximum trace length reduces from 10 inches (25.4 cm) to 7 inches (17.78 cm) for PCIe signals, and from 6 inches (15.24 cm) to 3 inches (7.62 cm) for SATA signals. PCIe HOST CONTROLLER RX 6 inches to 7 inches (15.24 cm to 17.78 cm) maximum TX CBTL 02042A SATA HOST CONTROLLER RX TX Mini-Card/mSATA CONNECTOR The topology of PCIe and SATA signals going to Mini-Card/mSATA connector is shown in Figure 5. Note that the CBTL02042A should be placed close to the Mini-Card/mSATA connector, with AC coupling capacitors placed on the side that is close to the host controllers, but adjacent to CBTL02042A. PCIe’s RX signals (PERp0, PERn0) to the host controller do not require AC coupling capacitors on the motherboard because they are placed on the Mini-Card. 2 inches to 3 inches (5.08 cm to 7.62 cm) maximum 019aaa991 Fig 5. AN11001 Application note Mini-Card/mSATA maximum trace length with CBTL02042A in place All information provided in this document is subject to legal disclaimers. Rev. 1 — 7 March 2011 © NXP B.V. 2011. All rights reserved. 9 of 17 AN11001 NXP Semiconductors CBTL02042A switching application for mSATA, PCIe Mini-Card It is recommended to minimize the use of vias and avoid impedance mismatch between traces. Also, the signal traces between the AC-coupling capacitors and the Mini-Card/mSATA connector, including those signals going through CBTL02042A, should be routed on the top layer only. Figure 6 and Figure 7 show the cross section view of the PCBs with signal path connecting from PCIe/SATA host controller to the connector. Note that the main route trace is placed on the inner signal layer in Figure 7, however it is strongly suggested for a PCB designer to route the main route on the top layer (as shown in Figure 6) by moving the second via (which is close to the AC-coupling capacitor) to the break-out region near the host controller. PCIe/SATA host controller connector vias AC-coupling capacitor CBTL02042A top layer inner layer (GND) breakout main route inner signal layer keep traces on top layer 019aaa992 Fig 6. PCB routing layers (cross-section view) with main route on top layer vias PCIe/SATA host controller AC-coupling capacitor connector CBTL02042A top layer inner layer (GND) breakout main route keep traces on top layer inner signal layer 019aaa993 Fig 7. PCB routing layers (cross-section view) with main route on inner signal layer Beside the trace length changes and routing layer recommendations, a PCB designer should also follow all other layout guidelines mentioned in the previous PCIe and SATA guideline sections. AN11001 Application note All information provided in this document is subject to legal disclaimers. Rev. 1 — 7 March 2011 © NXP B.V. 2011. All rights reserved. 10 of 17 AN11001 NXP Semiconductors CBTL02042A switching application for mSATA, PCIe Mini-Card 5. Alternative design using CBTL02042A or CBTL04082A 0 PCIe HOST CONTROLLER 1 0 select 1 SATA ↔ Mini-Card connector 0 PCIe ↔ Mini-Card connector SATA ↔ SATA HDD connector SATA CONNECTOR SATA HOST CONTROLLER Mini-Card/mSATA CONNECTOR In the design example above, only one interface is active at a time. For example, when a Mini-Card is inserted into the Mini-Card/mSATA connector socket, the PCI Express interface is selected, and the SATA interface is inactive. Instead of leaving SATA interface inactive in this configuration, a motherboard design may reclaim the SATA interface for a form-factor hard disk drive. A conceptual application diagram is shown in Figure 8 below, and it can be realized using either two CBTL02042As or one CBTL04082A/CBTL04083A. 019aab325 Fig 8. Alternative PCIe/SATA interface use case block diagram The following paragraphs discuss the design implementation in detail. While using either topology, a designer should pay special attention to the insertion loss caused by the multiplexers, and adjust the trace length accordingly. The SATA interface signals to Mini-Card/mSATA connector go through the multiplexer twice, thus insertion loss caused by the multiplexers would need to be accounted for twice as well. From the trace length calculation discussed in Section 4.3 “Topology with CBTL02042A as a switch for Mini-Card/mSATA”, a typical SATA trace length of 7 inches (17.78 cm) will need to deduct 5 inches (12.7 cm) to 6 inches (15.24 cm) to compensate the loss from the multiplexers. This only leaves 1 inch (2.54 cm) to 2 inches (5.08 cm) of SATA signal traces to route between the controller and the Mini-Card/mSATA connector. Depending on locations of the controllers and connectors on motherboards, routing such short SATA signal traces can be very difficult. AN11001 Application note All information provided in this document is subject to legal disclaimers. Rev. 1 — 7 March 2011 © NXP B.V. 2011. All rights reserved. 11 of 17 AN11001 NXP Semiconductors CBTL02042A switching application for mSATA, PCIe Mini-Card +B A1_N GND Mini-Card RX− A2_P Mini-Card RX+ A2_N VDD GND A3_P Mini-Card TX− Mini-Card TX+ A3_N GND VDD GND 39 VDD 40 XSD01 41 5 34 6 33 7 32 8 31 9 CBTL04082A 10 30 29 11 28 12 27 13 26 14 25 15 16 GND (exposed thermal pad) 24 23 17 22 18 PIN P21 P22 P23 P24 P25 P26 P27 P28 P29 P30 P31 P32 P33 P34 P35 P36 P37 P38 P39 P40 P41 P42 P43 P44 n.c. SEL 35 n.c. Mini-Card/mSATA connector socket VDD R2 33 kΩ 36 4 10 nF S2 B0_N SATA_TX− 10 nF S3 B1_P SATA_RX− 10 nF B1_N SATA_RX+ 10 nF S4 S5 C0_P S6 C0_N S7 C1_P C1_N P1 VDD B2_P PERn0 B2_N PERp0 B3_P 100 nF B3_N 100 nF C2_P 10 nF C2_N 10 nF C3_P 10 nF C3_N 10 nF PETn0 PETp0 to PCIe host controller A1_P 3 SATA_TX+ P2 P3 P4 P5 P6 P7 P8 P9 21 −B 37 B0_P P10 GND VDD 2 20 GND to GPIO S1 38 19 −A A0_N 1 VDD +A A0_P XSD23 to SATA host controller GND 42 VDD CARD_DET P11 P12 R1 33 kΩ P13 SEL P14 P15 019aab326 Fig 9. CBTL04082A/CBTL04083A implementation AN11001 Application note All information provided in this document is subject to legal disclaimers. Rev. 1 — 7 March 2011 © NXP B.V. 2011. All rights reserved. 12 of 17 AN11001 NXP Semiconductors CBTL02042A switching application for mSATA, PCIe Mini-Card S1 10 nF S2 10 nF S3 +B A1_P A1_N VSS 16 6 15 7 14 8 13 9 12 VDD C0_P 10 nF C1_N C0_N 10 nF C1_P C1_P 10 nF C0_N C1_N 10 nF C0_P 100 nF B1_N 100 nF B1_P B0_P 9 13 8 14 7 15 6 CBTL02042A 16 5 17 4 18 3 19 2 20 PETp0 12 PETn0 VSS to PCIe host controller B0_N PERp0 VDD VDD B1_N 10 CBTL02042A 10 SEL 5 B1_P SEL R2 33 kΩ A1_N A1_P VDD VSS A0_N A0_P XSD PERn0 VDD R1 33 kΩ SEL P1 PIN P21 P22 P23 P24 P25 P26 P27 P28 P29 P30 P31 P32 P33 P34 P35 P36 P37 P38 P39 P40 P41 P42 P43 P44 P2 P3 Mini-Card/mSATA connector socket −B 17 S7 1 VDD 4 B0_N VSS VSS 18 S6 11 A0_N 3 S5 B0_P VDD −A A0_P 19 11 +A 2 VSS to SATA host controller XSD S4 10 nF 20 1 VDD 10 nF P4 P5 P6 P7 P8 P9 P10 P11 P12 P13 P14 P15 to GPIO CARD_DET 019aab327 Fig 10. CBTL02042A implementation Note that PCB routing using a CBTL04082A/CBTL04083A is more difficult to implement than using two CBTL02042As. Signals from a PCI Express controller are connected to pin 26 to pin 29 of CBTL04082A/CBTL04083A, but these pins are encapsulated by SATA signals connecting between pins 22 to 25 and pins 31 to 34. Multiple vias are necessary to route PCI Express signals in this case, and using additional vias usually implies that extra insertion loss needs to be accounted for. PCB routing using two CBTL02042As topology will have a smoother high-speed signal flow without using any via. In addition, SATA and PCI Express signals are typically coming from the same Platform Controller Hub (PCH) located in the middle of the motherboard, and connectors are located on the board edge. The configuration shown in Figure 10 keeps signals to the controllers and to the connectors on the opposite sides of the multiplexers and fits this layout profile perfectly. When an mSATA device is not inserted in the Mini-Card/mSATA connector, SATA signals should be re-directed to the SATA HDD connector, regardless if a Mini-Card device is present or not. Table 4 summarizes all possible combinations of devices inserted in the Mini-Card/mSATA and SATA HDD connectors. AN11001 Application note All information provided in this document is subject to legal disclaimers. Rev. 1 — 7 March 2011 © NXP B.V. 2011. All rights reserved. 13 of 17 AN11001 NXP Semiconductors CBTL02042A switching application for mSATA, PCIe Mini-Card Table 4. Mini-Card/mSATA and SATA HDD device possible insertion combination SATA HDD connector Mini-Card/mSATA connector None SATA HDD None possible possible Mini-Card possible possible mSATA possible impossible (mSATA active) Circuits in Figure 9 and Figure 10 show automatic hardware selecting the SEL pins on the multiplexers utilizing an AND gate and an inverter, or a single 74LVC1G98. Logic is based on pin 43 and pin 21 on the Mini-Card/mSATA connector. This detection logic can also be implemented using a GPIO output from a processor based on the CARD_DET and SEL signal status. However, this is beyond the scope of this design guideline, and will not be discussed here. Table 5. Multiplexer SEL pin logic table CARD_DET signal state (pin 21) 0 0 1 1 card inserted inverted 1 card inserted inverted 1 card absent inverted 0 card absent inverted 0 SEL signal state (pin 43) SEL pin on multiplexers PCIe Mini-Card 0 Mini-Card 0 1 mSATA 1 SATA Mini-Card X (1) card absent 0 SATA HDD X (1) card absent 0 SATA HDD SATA HDD PCIe X PCIe X PCIe X To simplify the circuit diagrams, XSD pins on the multiplexers are also permanently tied to ground disabling device shutdown function. One can utilize pin 21 on Mini-Card connector and S1 or S7 pin on the SATA HDD connector to implement this shutdown feature on the multiplexers as shown below. VDD R2 33 kΩ pin 21 on Mini-Card connector S1/S7 pin on HDD connector to XSD pins R3 33 kΩ VDD 019aab381 Fig 11. Multiplexer XSD signal implementation 6. Conclusion mSATA and PCI Express Mini-Card are sharing the same physical connector type with minor pin definition modification. Automatic card detection and signal multiplexing function between SATA interface and PCI Express interface can be implemented using CBTL02042A. PCB design should account for the insertion loss by the multiplexer, and reduce the trace length accordingly. AN11001 Application note All information provided in this document is subject to legal disclaimers. Rev. 1 — 7 March 2011 © NXP B.V. 2011. All rights reserved. 14 of 17 AN11001 NXP Semiconductors CBTL02042A switching application for mSATA, PCIe Mini-Card 7. Abbreviations Table 6. AN11001 Application note Abbreviations Acronym Description CPU Central Processing Unit ECN Engineering Change Notice EMI ElectroMagnetic Interference ESR Equivalent Series Resistance HDD Hard Disk Drive mSATA mini SATA PCB Printed-Circuit Board PCH Platform Controller Hub PCI Peripheral Component Interconnect PCIe PCI Express SATA Serial Advanced Technology Attachment All information provided in this document is subject to legal disclaimers. Rev. 1 — 7 March 2011 © NXP B.V. 2011. All rights reserved. 15 of 17 AN11001 NXP Semiconductors CBTL02042A switching application for mSATA, PCIe Mini-Card 8. Legal information 8.1 Definitions Draft — The document is a draft version only. The content is still under internal review and subject to formal approval, which may result in modifications or additions. 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Suitability for use — NXP Semiconductors products are not designed, authorized or warranted to be suitable for use in life support, life-critical or safety-critical systems or equipment, nor in applications where failure or AN11001 Application note malfunction of an NXP Semiconductors product can reasonably be expected to result in personal injury, death or severe property or environmental damage. NXP Semiconductors accepts no liability for inclusion and/or use of NXP Semiconductors products in such equipment or applications and therefore such inclusion and/or use is at the customer’s own risk. Applications — Applications that are described herein for any of these products are for illustrative purposes only. NXP Semiconductors makes no representation or warranty that such applications will be suitable for the specified use without further testing or modification. Customers are responsible for the design and operation of their applications and products using NXP Semiconductors products, and NXP Semiconductors accepts no liability for any assistance with applications or customer product design. It is customer’s sole responsibility to determine whether the NXP Semiconductors product is suitable and fit for the customer’s applications and products planned, as well as for the planned application and use of customer’s third party customer(s). Customers should provide appropriate design and operating safeguards to minimize the risks associated with their applications and products. NXP Semiconductors does not accept any liability related to any default, damage, costs or problem which is based on any weakness or default in the customer’s applications or products, or the application or use by customer’s third party customer(s). Customer is responsible for doing all necessary testing for the customer’s applications and products using NXP Semiconductors products in order to avoid a default of the applications and the products or of the application or use by customer’s third party customer(s). NXP does not accept any liability in this respect. Export control — This document as well as the item(s) described herein may be subject to export control regulations. Export might require a prior authorization from national authorities. 8.3 Trademarks Notice: All referenced brands, product names, service names and trademarks are the property of their respective owners. All information provided in this document is subject to legal disclaimers. Rev. 1 — 7 March 2011 © NXP B.V. 2011. All rights reserved. 16 of 17 AN11001 NXP Semiconductors CBTL02042A switching application for mSATA, PCIe Mini-Card 9. Contents 1 2 3 4 4.1 4.2 4.3 5 6 7 8 8.1 8.2 8.3 9 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 Mini-Card and mSATA applications . . . . . . . . . 3 Switching circuit schematic . . . . . . . . . . . . . . . 6 Mini-Card/mSATA routing guidelines (summary) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 PCI Express routing guideline (without multiplexer in topology) . . . . . . . . . . . . 7 SATA routing guideline (without multiplexer in topology) . . . . . . . . . . . . 8 Topology with CBTL02042A as a switch for Mini-Card/mSATA . . . . . . . . . . . . . . . . . . . . . . . 9 Alternative design using CBTL02042A or CBTL04082A. . . . . . . . . . . . . . . . . . . . . . . . . . . 11 Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 Abbreviations . . . . . . . . . . . . . . . . . . . . . . . . . . 15 Legal information. . . . . . . . . . . . . . . . . . . . . . . 16 Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 Disclaimers . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 Trademarks. . . . . . . . . . . . . . . . . . . . . . . . . . . 16 Contents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 Please be aware that important notices concerning this document and the product(s) described herein, have been included in section ‘Legal information’. © NXP B.V. 2011. All rights reserved. For more information, please visit: http://www.nxp.com For sales office addresses, please send an email to: [email protected] Date of release: 7 March 2011 Document identifier: AN11001