PCI2050A PCI-to-PCI BRIDGE SCPS067 – MAY 2001 D D D D D D D Two 32-Bit, 66-MHz PCI Buses Configurable for PCI Power Management Interface Specification Provides CompactPCI Hot-Swap Functionality 3.3-V Core Logic With Universal PCI Interfaces Compatible With 3.3-V and 5-V PCI Signaling Environments Provides Internal Two-Tier Arbitration for up to Nine Secondary Bus Masters and Supports an External Secondary Bus Arbiter Burst Data Transfers With Pipeline Architecture to Maximize Data Throughput in Both Directions Independent Read and Write Buffers for Each Direction D D D D D D D D D D Up to Three Delayed Transactions in Both Directions Provides 10 Secondary PCI Clock Outputs Predictable Latency per PCI Local Bus Specification Propagates Bus Locking Supports Write Combining for Enhanced Data Throughput Supports Frame-to-Frame Delay of Only Four PCI Clocks From One Bus to Another Secondary Bus is Driven Low During Reset Provides VGA/Palette Memory and I/O, and Subtractive Decoding Options Advanced Submicron, Low-Power CMOS Technology Packaged in 208-Terminal QFP description This data sheet for PCI2050A lists only enhancements to PCI2050 and must be used in conjunction with PCI2050, PCI-to-PCI bridge, data manual (Literature number SCPS053A) The Texas Instruments PCI2050A PCI-to-PCI bridge provides a high performance connection path between two peripheral component interconnect (PCI) buses operating at a maximum bus frequency of 66-MHz. Transactions occur between masters on one and targets on another PCI bus, and the PCI2050A allows bridged transactions to occur concurrently on both buses. The bridge supports burst mode transfers to maximize data throughput, and the two bus traffic paths through the bridge act independently. The PCI2050A bridge is compliant with the PCI local bus specification, and can be used to overcome the electrical loading limits of 10 devices per PCI bus and one PCI device per extension slot by creating hierarchical buses. The PCI2050A provides two-tier internal arbitration for up to nine secondary bus masters and may be implemented with an external bus arbiter. The CompactPCI hot-swap extended PCI capability makes the PCI2050A an ideal solution for multifunction compact PCI cards and adapting single function cards to hot-swap compliance. The PCI2050A bridge is compliant with PCI-to-PCI bridge specification 1.1. The PCI2050A provides compliance for PCI Power Management 1.0 and 1.1. The PCI2050A has been designed to lead the industry in power consumption and data throughput. An advanced CMOS process achieves low system power consumption while operating at PCI clock rates up to 66-MHz. Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet. CompactPCI is a trademark of PICMG-PCI Industrial Computer Manufacturers Group, Inc. All other trademarks are the property of their respective owners. Copyright 2001, Texas Instruments Incorporated PRODUCTION DATA information is current as of publication date. Products conform to specifications per the terms of Texas Instruments standard warranty. Production processing does not necessarily include testing of all parameters. POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 1 PCI2050A PCI-to-PCI BRIDGE SCPS067 – MAY 2001 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 PCI2050A 104 103 102 101 100 99 98 97 96 95 94 93 92 91 90 89 88 87 86 85 84 83 82 81 80 79 78 77 76 75 74 73 72 71 70 69 68 67 66 65 64 63 62 61 60 59 58 57 56 55 54 53 VCC S_REQ1 S_REQ2 S_REQ3 S_REQ4 S_REQ5 S_REQ6 S_REQ7 S_REQ8 S_GNT0 S_GNT1 GND S_GNT2 S_GNT3 S_GNT4 S_GNT5 S_GNT6 S_GNT7 S_GNT8 GND S_CLK S_RST S_CFN GP103/HSSWITCH GPIO2 VCC GPIO1 GPIO0 S_CLKOUT0 S_CLKOUT1 GND S_CLKOUT2 S_CLKOUT3 VCC S_CLKOUT4 S_CLKOUT5 GND S_CLKOUT6 S_CLKOUT7 VCC S_CLKOUT8 S_CLKOUT9 P_RST BPCCE P_CLK P_GNT P_REQ GND P_AD31 P_AD30 VCC GND 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 VCC GND S_AD11 GND S_AD12 S_AD13 VCC S_AD14 S_AD15 GND S_C/BE1 S_PAR S_SERR VCC S_PERR S_LOCK S_STOP GND S_DEVSEL S_TRDY S_IRDY VCC S_FRAME S_C/BE2 GND S_AD16 S_AD17 VCC S_AD18 S_AD19 GND S_AD20 S_AD21 VCC S_AD22 S_AD23 GND S_C/BE3 S_AD24 VCC S_AD25 S_AD26 GND S_AD27 S_AD28 VCC S_AD29 S_AD30 GND S_AD31 S_REQ0 VCC 156 155 154 153 152 151 150 149 148 147 146 145 144 143 142 141 140 139 138 137 136 135 134 133 132 131 130 129 128 127 126 125 124 123 122 121 120 119 118 117 116 115 114 113 112 111 110 109 108 107 106 105 GND MS0 S_AD10 S_M66ENA S_AD9 VCC S_AD8 S_C/BE0 GND S_AD7 S_AD6 VCC S_AD5 S_AD4 GND S_AD3 S_AD2 VCC S_AD1 S_AD0 GND S_VCCP TRST TCK TMS VCC TDO TDI HSLED HSENUM MSK_IN CONFIG66 P_VCCP GND P_AD0 P_AD1 VCC P_AD2 P_AD3 GND P_AD4 P_AD5 VCC P_AD6 P_AD7 GND P_C/BE0 P_AD8 VCC P_AD9 MS1 VCC PDV LOW-PROFILE QUAD FLAT PACKAGE TOP VIEW 2 POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 GND VCC P_M66ENA P_AD10 GND P_AD11 P_AD12 VCC P_AD13 P_AD14 GND P_AD15 P_C/BE1 VCC P_PAR P_SERR P_PERR P_LOCK GND P_STOP P_DEVSEL P_TRDY P_IRDY VCC P_FRAME P_C/BE2 GND P_AD16 P_AD17 VCC P_AD18 P_AD19 GND P_AD20 P_AD21 VCC P_AD22 P_AD23 GND P_IDSEL P_C/BE3 P_AD24 VCC P_AD25 P_AD26 GND P_AD27 P_AD28 VCC P_AD29 GND VCC PCI2050A PCI-to-PCI BRIDGE SCPS067 – MAY 2001 Terminal Functions primary PCI system terminals TERMINAL I/O DESCRIPTION 45 I Primary PCI bus clock. P_CLK provides timing for all transactions on the primary PCI bus. All primary PCI signals are sampled at rising edge of P_CLK. 43 I PCI reset. When the primary PCI bus reset is asserted, P_RST causes the bridge to put all output buffers in a high-impedance state and reset all internal registers. When asserted, the device is completely nonfunctional. During P_RST, the secondary interface is driven low. After P_RST is deasserted, the bridge is in its default state. NAME NO. P_CLK P_RST primary PCI address and data terminals TERMINAL NAME NO. P_AD31 P_AD30 P_AD29 P_AD28 P_AD27 P_AD26 P_AD25 P_AD24 P_AD23 P_AD22 P_AD21 P_AD20 P_AD19 P_AD18 P_AD17 P_AD16 P_AD15 P_AD14 P_AD13 P_AD12 P_AD11 P_AD10 P_AD9 P_AD8 P_AD7 P_AD6 P_AD5 P_AD4 P_AD3 P_AD2 P_AD1 P_AD0 49 50 55 57 58 60 61 63 67 68 70 71 73 74 76 77 93 95 96 98 99 101 107 109 112 113 115 116 118 119 121 122 P_C/BE3 P_C/BE2 P_C/BE1 P_C/BE0 64 79 92 110 I/O DESCRIPTION I/O Primary address/data bus. These signals make up the multiplexed PCI address and data bus on the primary interface. During the address phase of a primary bus PCI cycle, P_AD31–P_AD0 contain a 32-bit address or other destination information. During the data phase, P_AD31–P_AD0 contain data. I/O Primary bus commands and byte enables. These signals are multiplexed on the same PCI terminals. During the address phase of a primary bus PCI cycle, P_C/BE3–P_C/BE0 define the bus command. During the data phase, this 4-bit bus is used as byte enables. The byte enables determine which byte paths of the full 32-bit data bus carry meaningful data. P_C/BE0 applies to byte 0 (P_AD7–P_AD0), P_C/BE1 applies to byte 1 (P_AD15–P_AD8), P_C/BE2 applies to byte 2 (P_AD23–P_AD16), and P_C/BE3 applies to byte 3 (P_AD31–P_AD24). POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 3 PCI2050A PCI-to-PCI BRIDGE SCPS067 – MAY 2001 Terminal Functions (Continued) primary PCI interface control terminals TERMINAL 4 I/O DESCRIPTION 84 I/O Primary device select. The bridge asserts P_DEVSEL to claim a PCI cycle as the target device. As a PCI master on the primary bus, the bridge monitors P_DEVSEL until a target responds. If no target responds before time-out occurs, then the bridge terminates the cycle with a master abort. P_FRAME 80 I/O Primary cycle frame. P_FRAME is driven by the master of a primary bus cycle. P_FRAME is asserted to indicate that a bus transaction is beginning, and data transfers continue while this signal is asserted. When P_FRAME is deasserted, the primary bus transaction is in the final data phase. P_GNT 46 I Primary bus grant to bridge. P_GNT is driven by the primary PCI bus arbiter to grant the bridge access to the primary PCI bus after the current data transaction has completed. P_GNT may or may not follow a primary bus request, depending on the primary bus arbitration algorithm. NAME NO. P_DEVSEL P_IDSEL 65 I Primary initialization device select. P_IDSEL selects the bridge during configuration space accesses. P_IDSEL can be connected to one of the upper 24 PCI address lines on the primary PCI bus. Note: There is no IDSEL signal interfacing the secondary PCI bus; thus, the entire configuration space of the bridge can only be accessed from the primary bus. P_IRDY 82 I/O Primary initiator ready. P_IRDY indicates ability of the primary bus master to complete the current data phase of the transaction. A data phase is completed on a rising edge of P_CLK where both P_IRDY and P_TRDY are asserted. Until P_IRDY and P_TRDY are both sampled asserted, wait states are inserted. P_LOCK 87 I/O Primary PCI bus lock. P_LOCK is used to lock the primary bus and gain exclusive access as a bus master. P_PAR 90 I/O Primary parity. In all primary bus read and write cycles, the bridge calculates even parity across the P_AD and P_C/BE buses. As a bus master during PCI write cycles, the bridge outputs this parity indicator with a one-P_CLK delay. As a target during PCI read cycles, the calculated parity is compared to the parity indicator of the master; a miscompare can result in a parity error assertion (P_PERR). P_PERR 88 I/O Primary parity error indicator. P_PERR is driven by a primary bus PCI device to indicate that calculated parity does not match P_PAR when P_PERR is enabled through bit 6 of the command register (PCI offset 04h). P_REQ 47 O Primary PCI bus request. Asserted by the bridge to request access to the primary PCI bus as a master. P_SERR 89 O Primary system error. Output pulsed from the bridge when enabled through the command register (PCI offset 04h). indicating a system error has occurred. The bridge needs not be the target of the primary PCI cycle to assert this signal. When bit 6 is enabled in the bridge control register (PCI offset 3Eh), this signal also pulses, indicating that a system error has occurred on one of the subordinate buses downstream from the bridge. P_STOP 85 I/O Primary cycle stop signal. This signal is driven by a PCI target to request that the master stop the current primary bus transaction. This signal is used for target disconnects and is commonly asserted by target devices which do not support burst data transfers. P_TRDY 83 I/O Primary target ready. P_TRDY indicates the ability of the primary bus target to complete the current data phase of the transaction. A data phase is completed upon a rising edge of P_CLK where both P_IRDY and P_TRDY are asserted. Until both P_IRDY and P_TRDY are asserted, wait states are inserted. POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 PCI2050A PCI-to-PCI BRIDGE SCPS067 – MAY 2001 Terminal Functions (Continued) secondary PCI system terminals TERMINAL I/O DESCRIPTION 42 41 39 38 36 35 33 32 30 29 O Secondary PCI bus clocks. Provide timing for all transactions on the secondary PCI bus. Each secondary bus device samples all secondary PCI signals at the rising edge of its corresponding S_CLKOUT input. 21 I Secondary PCI bus clock input. This input synchronizes the PCI2050 to the secondary bus clocks. NAME NO. S_CLKOUT9 S_CLKOUT8 S_CLKOUT7 S_CLKOUT6 S_CLKOUT5 S_CLKOUT4 S_CLKOUT3 S_CLKOUT2 S_CLKOUT1 S_CLKOUT0 S_CLK S_CFN 23 I Secondary external arbiter enable. When this signal is high, the secondary external arbiter is enabled. When the external arbiter is enabled, the PCI2050 S_REQ0 terminal is reconfigured as a secondary bus grant input to the bridge and S_GNT0 is reconfigured as a secondary bus master request to the external arbiter on the secondary bus. S_RST 22 O Secondary PCI reset. S_RST is a logical OR of P_RST and the state of the secondary bus reset bit (bit 6) of the bridge control register (PCI offset 3Eh). S_RST is asynchronous with respect to the state of the secondary interface CLK signal. POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 5 PCI2050A PCI-to-PCI BRIDGE SCPS067 – MAY 2001 Terminal Functions (Continued) secondary PCI address and data terminals TERMINAL 6 I/O DESCRIPTION I/O Secondary address/data bus. These signals make up the multiplexed PCI address and data bus on the secondary interface. During the address phase of a secondary bus PCI cycle, S_AD31–S_AD0 contain a 32-bit address or other destination information. During the data phase, S_AD31–S_AD0 contain data. 194 180 167 149 I/O Secondary bus commands and byte enables. These signals are multiplexed on the same PCI terminals. During the address phase of a secondary bus PCI cycle, S_C/BE3–S_C/BE0 define the bus command. During the data phase, this 4-bit bus is used as byte enables. The byte enables determine which byte paths of the full 32-bit data bus carry meaningful data. S_C/BE0 applies to byte 0 (S_AD7–S_AD0), S_C/BE1 applies to byte 1 (S_AD15–S_AD8), S_C/BE2 applies to byte 2 (S_AD23–S_AD16), and S_C/BE3 applies to byte 3 (S_AD31–S_AD24). S_DEVSEL 175 I/O Secondary device select. The bridge asserts S_DEVSEL to claim a PCI cycle as the target device. As a PCI master on the secondary bus, the bridge monitors S_DEVSEL until a target responds. If no target responds before time-out occurs, then the bridge terminates the cycle with a master abort. S_FRAME 179 I/O Secondary cycle frame. S_FRAME is driven by the master of a secondary bus cycle. S_FRAME is asserted to indicate that a bus transaction is beginning and data transfers continue while S_FRAME is asserted. When S_FRAME is deasserted, the secondary bus transaction is in the final data phase. S_GNT8 S_GNT7 S_GNT6 S_GNT5 S_GNT4 S_GNT3 S_GNT2 S_GNT1 S_GNT0 19 18 17 16 15 14 13 11 10 O Secondary bus grant to the bridge. The bridge provides internal arbitration and these signals are used to grant potential secondary PCI bus masters access to the bus. Ten potential masters (including the bridge) can be located on the secondary PCI bus. When the internal arbiter is disabled, S_GNT0 is reconfigured as an external secondary bus request signal for the bridge. NAME NO. S_AD31 S_AD30 S_AD29 S_AD28 S_AD27 S_AD26 S_AD25 S_AD24 S_AD23 S_AD22 S_AD21 S_AD20 S_AD19 S_AD18 S_AD17 S_AD16 S_AD15 S_AD14 S_AD13 S_AD12 S_AD11 S_AD10 S_AD9 S_AD8 S_AD7 S_AD6 S_AD5 S_AD4 S_AD3 S_AD2 S_AD1 S_AD0 206 204 203 201 200 198 197 195 192 191 189 188 186 185 183 182 165 164 162 161 159 154 152 150 147 146 144 143 141 140 138 137 S_C/BE3 S_C/BE2 S_C/BE1 S_C/BE0 POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 PCI2050A PCI-to-PCI BRIDGE SCPS067 – MAY 2001 Terminal Functions (Continued) secondary PCI interface control terminals TERMINAL I/O DESCRIPTION 177 I/O Secondary initiator ready. S_IRDY indicates the ability of the secondary bus master to complete the current data phase of the transaction. A data phase is completed on a rising edge of S_CLK where both S_IRDY and S_TRDY are asserted; until S_IRDY and S_TRDY are asserted, wait states are inserted. 172 I/O Secondary PCI bus lock. S_LOCK is used to lock the secondary bus and gain exclusive access as a master. NAME NO. S_IRDY S_LOCK S_PAR 168 I/O Secondary parity. In all secondary bus read and write cycles, the bridge calculates even parity across the S_AD and S_C/BE buses. As a master during PCI write cycles, the bridge outputs this parity indicator with a one-S_CLK delay. As a target during PCI read cycles, the calculated parity is compared to the master parity indicator. A miscompare can result in a parity error assertion (S_PERR). S_PERR 171 I/O Secondary parity error indicator. S_PERR is driven by a secondary bus PCI device to indicate that calculated parity does not match S_PAR when enabled through the command register (PCI offset 04h). S_REQ8 S_REQ7 S_REQ6 S_REQ5 S_REQ4 S_REQ3 S_REQ2 S_REQ1 S_REQ0 9 8 7 6 5 4 3 2 207 I Secondary PCI bus request signals. The bridge provides internal arbitration, and these signals are used as inputs from secondary PCI bus masters requesting the bus. Ten potential masters (including the bridge) can be located on the secondary PCI bus. When the internal arbiter is disabled, the S_REQ0 signal is reconfigured as an external secondary bus grant for the bridge. S_SERR 169 I Secondary system error. S_SERR is passed through the primary interface by the bridge if enabled through the bridge control register (PCI offset 3Eh). S_SERR is never asserted by the bridge. S_STOP 173 I/O Secondary cycle stop signal. S_STOP is driven by a PCI target to request that the master stop the current secondary bus transaction. S_STOP is used for target disconnects and is commonly asserted by target devices that do not support burst data transfers. S_TRDY 176 I/O Secondary target ready. S_TRDY indicates the ability of the secondary bus target to complete the current data phase of the transaction. A data phase is completed on a rising edge of S_CLK where both S_IRDY and S_TRDY are asserted; until S_IRDY and S_TRDY are asserted, wait states are inserted. POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 7 PCI2050A PCI-to-PCI BRIDGE SCPS067 – MAY 2001 Terminal Functions (Continued) miscellaneous terminals TERMINAL NAME NO. I/O DESCRIPTION BPCCE 44 I Bus/power clock control management terminal. When signal BPCCE is tied high, and when the PCI2050 is placed in the D3 power state, it enables the PCI2050 to place the secondary bus in the B2 power state. The PCI2050 disables the secondary clocks and drives them to 0. When tied low, placing the PCI2050 in the D3 power state has no effect on the secondary bus clocks. GPIO3/HSSWITCH GPIO2 GPIO1 GPIO0 24 25 27 28 I General-purpose I/O terminals GPIO3 is HSSWITCH in cPCI mode. HSSWITCH provides the status of the ejector handle switch to the cPCI logic. HSENUM 127 O Hot–swap ENUM HSLED 128 O Hot-swap LED output MS0 155 I Mode select 0 MS1 106 I Mode select 1 P_M66ENA 102 I Primary interface 66 MHz enable. This input-only signal pin is used to designate the primary interface bus speed. This signal should be pulled low for 33 MHz operation on the primary bus. In this case S_M66ENA signal will be driven low by the PCI2050A, forcing the secondary bus to run at 33 MHz. For 66-MHz operation, this signal should be pulled high. CONFIG66 125 I Configure 66 MHz operation. This input-only pin is used to specify if PCI2050A is capable of running at 66 MHz. If this terminal is tied high, then device can be run at 66 MHz. If this pin is tied low, then PCI2050A can only function under the 33 MHz PCI specification. I/O Secondary 66-MHz enable terminal. This signal is used to designate the secondary bus speed. If the P_M66ENA is driven low, then this signal is driven low by the PCI2050A forcing secondary bus to run at 33 MHz. If the primary bus is running at 66 MHz (P_M66ENA is high), then S_M66ENA is an input and should be externally pulled high for the secondary bus to operate at 66 MHz or pulled low for secondary bus to operate at 33 MHz. Note that S_M66ENA is an open drained output. S_M66ENA 153 JTAG interface terminals TERMINAL 8 I/O DESCRIPTION NAME NO. TCK 133 I JTAG boundary-scan clock. TCK is the clock controlling the JTAG logic. TDI 129 I JTAG serial data in. TDI is the serial input through which JTAG instructions and test data enter the JTAG interface. The new data on TDI is sampled on the rising edge of TCK. TDO 130 O JTAG serial data out. TDO is the serial output through which test instructions and data from the test logic leave the PCI2050. TMS 132 I JTAG test mode select. TMS causes state transitions in the test access port controller. TRST 134 I JTAG TAP reset. When TRST is asserted low, the TAP controller is asynchronously forced to enter a reset state and initialize the test logic. POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 PCI2050A PCI-to-PCI BRIDGE SCPS067 – MAY 2001 Terminal Functions (Continued) power supply terminals TERMINAL DESCRIPTION NAME NO. GND 12, 20, 31, 37, 48, 52, 54, 59, 66, 72, 78, 86, 94, 100, 104, 111, 117, 123, 136, 142, 148, 156, 158, 160, 166, 174, 181, 187, 193, 199, 205 Device ground terminals VCC 1, 26, 34, 40, 51, 53, 56, 62, 69, 75, 81, 91, 97, 103, 105, 108, 114, 120, 131, 139, 145, 151, 157, 163, 170, 178, 184, 190, 196, 202, 208 Power-supply terminal for core logic (3.3 V) P_VCCP 124 Primary bus-signaling environment supply. P_VCCP is used in protection circuitry on primary bus I/O signals. S_VCCP 135 Secondary bus-signaling environment supply. S_VCCP is used in protection circuitry on secondary bus I/O signals. detailed description The PCI2050 is a bridge between two PCI buses and is compliant with both the PCI local bus specification and the PCI-to-PCI bridge specification. The bridge supports two 32-bit PCI buses operating at a maximum of 66 MHz. The primary and secondary buses operate independently in either 3.3-V or 5-V signaling environment. The core logic of the bridge, however, is powered at 3.3 V to reduce power consumption. Host software interacts with the bridge through internal registers. These registers provide the standard PCI status and control for both the primary and secondary buses. Many vendor-specific features that exist in the TI extension register set are included in the bridge. The PCI configuration header of the bridge is only accessible from the primary PCI interface. The bridge provides internal arbitration for the nine possible bus masters, and provides each with a dedicated active low request/grant pair (REQ/GNT). The arbiter features a two-tier rotational scheme with the PCI2050A bridge defaulting to the highest priority tier. The PCI2050A also supports external arbitration. Upon system power up, power-on self test (POST) software configures the bridge according to the devices that exist on subordinate buses, and enables performance-enhancing features of the PCI2050. In a typical system, this is the only communication with the bridge internal register set. write combining PCI2050A supports write combining for upstream and downstream transactions. This feature is used to combine separate sequential memory write transactions into a single burst transactions. This feature can only be used if the address of the next memory write transaction is the next sequential address after the address of the last double word of the previous memory transaction. For example if the current memory transaction ends at address X and next memory transaction starts at address X+1, then PCI2050A combines both transactions into a single transaction. The write combining feature of PCI2050A is enabled by default on power on reset. It can also be disabled by setting bit 0 of the TI diagnostics register at offset F0h to 1. POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 9 PCI2050A PCI-to-PCI BRIDGE SCPS067 – MAY 2001 detailed description (continued) 66-MHz operation PCI2050A supports two 32-bit PCI buses operating at a maximum frequency of 66-MHz. The 66-MHz clocking requires three terminals P_M66ENA, S_M66ENA and CONFIG66. To enable 66 MHz operation, the signal CONFIG66 must be tied high on the board. This sets the 66 MHz capable bit in the primary and secondary status register. The P_M66ENA and S_M66ENA must not be pulled high unless CONFIG66 is also high. The signals P_ M66ENA and S_ M66ENA indicate whether the primary or secondary interfaces are working at 66 MHz. This information is needed to control the frequency of the secondary bus. Note that PCI local bus specification 2.2 restricts clock frequency changes above 33 MHz to during reset only. The following frequency combinations are supported on the primary and secondary buses in PCI2050A: D D D 66 MHz primary bus, 66 MHz secondary bus 66 MHz primary bus, 33 MHz secondary bus 33 MHz primary bus, 33 MHz secondary bus The PCI2050A does not support 33-MHz primary/66-MHz secondary bus operation. If CONFIG66 is high and P_M66ENA is low, the PCI2050A pulls down S_M66ENA to indicate that secondary bus is running at 33 MHz. The 2050A generates the clock signals S_CLKOUT[9:0] for the secondary bus devices and its own interface. It divides the P_CLK by two to generate the secondary clock outputs whenever the primary bus is running at 66 MHz and secondary bus is running at 33 MHz. The bridge detects this condition by polling P_M66ENA and S_M66ENA. 10 POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 PCI2050A PCI-to-PCI BRIDGE SCPS067 – MAY 2001 bridge configuration header The bridge configuration header for PCI2050A is exactly the same as the bridge configuration header for PCI2050 except for the following registers. The PCI2050A bridge is a single-function PCI device. The configuration header is in compliance with the PCI-to-PCI Bridge Specification 1.1. Table 1 shows the PCI configuration header, which includes the predefined portion of the bridge configuration space. The PCI configuration offset is shown in the right column under the OFFSET heading. Table 1. Bridge Configuration Header REGISTER NAME OFFSET Device ID Vendor ID 00h Status Command 04h Class code BIST Header type Primary latency timer Revision ID 08h Cache line size 0Ch Base address 0 10h Base address 1 Secondary bus latency timer Subordinate bus number 14h Secondary bus number Primary bus number 18h I/O limit I/O base 1Ch Secondary status Memory limit Memory base 20h Prefetchable memory limit Prefetchable memory base 24h Prefetchable base upper 32 bits 28h Prefetchable limit upper 32 bits 2Ch I/O limit upper 16 bits I/O base upper 16 bits Reserved Capability pointer Expansion ROM base address 30h 34h 38h Bridge control Interrupt pin Interrupt line 3Ch Arbiter control Extended diagnostic Chip control 40h Reserved GPIO input data GPIO output enable Reserved P_SERR status 44h–60h GPIO output data P_SERR event disable Secondary clock control Reserved Power management capabilities Data PMCSR bridge support Hot swap control status PM capability ID Power management control/status HS next item pointer HS capability ID Reserved DCh E0h E4h E8h–EFh Reserved Diagnostics Reserved POST OFFICE BOX 655303 68h 6Ch–D8h PM next item pointer Reserved 64h F0 F4–FF • DALLAS, TEXAS 75265 11 PCI2050A PCI-to-PCI BRIDGE SCPS067 – MAY 2001 bridge configuration header (continued) status register The bit 5 in status register is hardwired to 0 in PCI2050. However, in PCI2050A it indicates whether the primary PCI interface is 66-MHz capable or not. Bit 15 14 13 12 11 10 9 8 Name 7 6 5 4 3 2 1 0 Status Type R/W R/W R/W R/W R/W R R R/W R R R R R R R R Default 0 0 0 0 0 0 1 0 1 0 0 1 0 0 0 0 Register: Type: Offset: Default: Status Read-only, read/write (see individual bit descriptions) 06h 0290h Table 2. Status Register BIT TYPE 15-6 Same as PCI2050 5 R 4-0 Same as PCI2050 FUNCTION Same as PCI2050. 66-MHz capable. Bit 5 indicates whether the primary interface is 66 MHz capable. It reads as 0 when CONFIG66 is tied low to indicate that PCI2050A is not 66-MHz capable and reads as 1 when CONFIG66 is tied high to indicate that the primary bus is 66-MHz capable. Same as PCI2050. revision ID register The revision ID register indicates the silicon version of PCI2050A. Bit 7 6 5 4 Type R R R R Default 0 0 0 0 Name Register: Type: Offset: Default: 12 3 2 1 0 R R R R 0 0 0 1 Revision ID Revision ID Read-only 08h 01h POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 PCI2050A PCI-to-PCI BRIDGE SCPS067 – MAY 2001 bridge configuration header (continued) secondary status register The bit 5 in the status register is hardwired to 0 in PCI2050. However, in PCI2050A it indicates whether the primary PCI interface is 66-MHz capable. Bit 15 14 13 12 11 10 9 Name 8 7 6 5 4 3 2 1 0 Secondary Status Type R/W R/W R/W R/W R/W R R R/W R R R R R R R R Default 0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 0 Register: Type: Offset: Default: Secondary Status Read-only, read/write (see individual bit descriptions) IEh 0200 Table 3. Status Register BIT TYPE 15-6 Same as PCI2050 FUNCTION 5 R 4-0 Same as PCI2050 Same as PCI2050. 66-MHz capable. Bit 5 indicates whether the primary interface is 66-MHz capable. It reads as 0 when CONFIG66 is tied low to indicate that PCI2050A is not 66 MHz capable and reads as 1 when CONFIG66 is tied high to indicate that the primary bus is 66-MHz capable. Same as PCI2050. extension registers The extension registers for PCI2050A are exactly the same as the extension registers for PCI2050 except for the following registers. diagnostics register The register is used to enable or disable posted write combing of PCI2050A. Bit 15 14 13 12 11 10 9 Type R R R R R R R R Default 0 0 0 0 0 0 1 0 Name 8 7 6 5 4 3 2 1 0 R R R R R R R R/W 0 0 0 0 0 0 0 0 TI Diagnostics Register: Type: Offset: Default: TI Diagnostics Read-only, read/write (see individual bit descriptions) F0h 0000h Table 4. TI Diagnostics Register BIT TYPE 15-6 R 0 R/W FUNCTION Reserved. Bit 15–1 return 0s when read. Disable posted write combining. 0: Enable posted write combining (Default) 1: Disable posted write combining POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 13 PCI2050A PCI-to-PCI BRIDGE SCPS067 – MAY 2001 electrical data 66-MHz PCI clock signal ac parameters The ac specification consists of input requirements and output responses. The input requirements consists of setup and hold times, pulse widths, and high and low times. Output responses are delays from clock to signal. The ac specifications are defined are separately for each clock domain within the PCI2050A. Figure 1 shows the ac parameters measurements for P_CLK and S_CLK signals. tc th P_CLK tl Vt(1) Vt(2) Vt(3) tr tr ts ts th S_CLK tl Vt(1) Vt(2) Vt(3) tr tr tc NOTE: Vt(1) – 2.0 V for 5-V clocks; 0.5 VCC for 3.3-V clocks Vt(2) – 1.5 V for 5-V clocks; 0.4 VCC for 3.3-V clocks Vt(3) – 0.8 V for 5-V clocks; 0.3 VCC for 3.3-V clocks Figure 1. PCI Clock Signal AC Parameter Measurements 66 MHz PCI clock signal ac parameters PARAMETER MIN tc t(h) P_CLK, S_CLK cycle time 15 P_CLK, S_CLK high time 6 t(l) t(PSS) P_CLK, S_CLK low time td(SCLK) tr(SCLK) MAX 30 ns ns 6 ns 1.5 4 V/ns Delay from P_CLK to S_CLK 0 7 ns P_CLK rising to S_CLK rising 0 7 ns tf(SCLK) td(skew) P_CLK falling to S_CLK falling 0 7 ns S_CLK0 duty cycle skew from P_CLK duty cycle 0.750 ns tsk S_CLKx to SCLKy 0.500 ns 14 P_CLK, S_CLK slew rate (0.2 Vcc to 0.6 Vcc) UNIT POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 PCI2050A PCI-to-PCI BRIDGE SCPS067 – MAY 2001 electrical data (continued) 66-MHz PCI signal timing specifications Figure 2 illustrates the PCI signal timing specification. CLK Vtest ÎÎÎÎ ÎÎÎÎ ÎÎÎÎ tv Output ÎÎÎÎÎÎÎ ÎÎÎÎÎÎÎ ÎÎÎÎÎÎÎ t(inval) Valid toff ton th tsu Valid Input NOTE: Vtest – 1.5 V for 5-V signals; 0.4 VCC for 3.3-V signals Figure 2. PCI Signal Timing Measurement Conditions 66-MHz PCI signal timing PARAMETER MIN MAX UNIT tv(bus) tv(ptp) CLK to signal valid delay - bused signals (see Notes 1, 2, and 3) 2 6 ns CLK to signal valid delay – point to point (see Notes 1, 2, and 3) 2 6 ns ton toff Float to active delay (see Notes 1, 2, and 3) 2 tsu(bus) tsu(ptp) Input setup time to CLK– bused signal (see Notes 1, 2, and 3) 3 ns Input setup time to CLK – point-to-point (see Notes 1, 2, and 3) 5 ns Active to float delay (see Notes 1, 2, and 3) ns 14 ns th Input signal hold time from CLK (see Notes 1 and 2) 0 ns NOTES: 1. See Figure 2 2. All primary interface signals are synchronized to P_CLK and all secondary interface signals are synchronized to S_CLK. 3. Bused signals are as follows: P_AD, P_C/BE, P_PAR, P_PERR, P_SERR, P_FRAME, P_IRDY, P_TRDY, P_LOCK, P_DEVSEL, P_STOP, P_IDSEL, S_AD, S_C/BE, S_PAR, S_PERR, S_SERR, S_FRAME, S_IRDY, S_TRDY, S_LOCK, S_DEVSEL, S_STOP Point-to-point signals are as follows: P_REQ, S_REQx, P_GNT, S_GNTx POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 15 PCI2050A PCI-to-PCI BRIDGE SCPS067 – MAY 2001 MECHANICAL DATA PDV (S-PQFP-G208) PLASTIC QUAD FLATPACK 156 105 157 104 0,27 0,17 0,08 M 0,50 0,13 NOM 208 53 1 52 Gage Plane 25,50 TYP 28,05 SQ 27,95 0,25 0,05 MIN 0°- 7° 30,20 SQ 29,80 0,75 0,45 1,45 1,35 Seating Plane 0,08 1,60 MAX 4087729/D 11/98 NOTES: A. All linear dimensions are in millimeters. B. This drawing is subject to change without notice. C. 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