Abstract: This application note describes the hardware and software differences between the Dallas Semiconductor DS21Q44 and the DS21Q43A quad port framer devices. The DS21Q44 quad E1 framer, offers a broader feature set while retaining the original features of the DS21Q43A. As such, the designer must decide on what changes need to be made in software and hardware when migrating to the DS21Q44 from the DS21Q43A quad E1 framer. Any designer who is thinking of upgrading an existing design to use the DS21Q44 should read this application note. The application note contains detailed information for software migration such as: register location changes, how individual functions have changed from the DS21Q43A to the DS21Q44, and which new functions are available on the DS21Q44. It also covers migration for the hardware interface and covers new functions that are available in the DS21Q44. In the end, the designer should have enough information to easily migrate an existing design which uses the DS21Q43A to the DS21Q44 device. Overview This application note highlights the differences between the DS21Q44 and the DS21Q43A Quad E1 framers. The DS21Q44 is a superset of the DS21Q43A. The DS21Q44 is offered in a 3.3V version with 5V tolerant I/O. All of the original features of the DS21Q43A (except the loss-of-receive clock status bit) have been retained. Software created for the DS21Q43A is transferable to the DS21Q44 with minimal effort. Additional Functionality New Features Data Sheet Section Framer Mode Select (FMS) hardware pin provides DS21Q43A emulation mode 1 8.192MHz clock synthesizer 1, 3 Expanded receive and transmit elastic store reset functions 6 Device identification register 6 Automatic RAI generation to ETS 300 011 specifications 6 RCL, RLOS, RRA, and RUA1 alarms now interrupt on change of state 7 Ability to monitor DS0 channel in both the transmit and receive paths 9 Additional hardware signaling capability Receive signaling reinsertion to a backplane multiframe sync Signaling freezing 10 Per-channel loopback capability 11 Per-channel idle control 11 HDLC controller 64-byte buffers Can be used on Sa bits or DS0 channels 15 8Mbps interleaved PCM bus operation 16 JTAG support 17 3.3V operation with 5V tolerant I/O 19 Changes In Register Definitions When implementing the new features of the DS21Q44, a priority was placed on preserving the DS21Q43A's register map to facilitate code migration from existing DS21Q43A designs. This section highlights register additions and differences found in the DS21Q44. Register Map Comparison Address R/W DS21Q44 Register DS21Q43A Register 00 R RBPV or Code Violation Count 1 Same 01 R BPV or Code Violation Count 2 Same 02 R CRC4 Error Count 1/FAS Error Count 1 Same 03 R CRC4 Error Count 2 Same 04 R E-Bit Count 1/FAS Error Count 2 Same 05 R E-Bit Count 2 Same 06 R/W Status 1 Bit Difference 07 R/W Status 2 Bit Difference 08 R/W Receive Information Bit Difference 09 R/W Test 2 Not Used 0A µ Not Used Not Used 0B µ Not Used Not Used 0C µ Not Used Not Used 0D µ Not Used Not Used 0E µ Not Used Not Used 0F R Device ID Not Used 10 R/W Receive Control 1 Same 11 R/W Receive Control 2 Same 12 R/W Transmit Control 1 Same 13 R/W Transmit Control 2 Same 14 R/W Common Control 1 Same 15 R/W Test 1 Same 16 R/W Interrupt Mask 1 Bit Difference 17 R/W Interrupt Mask 2 Same 18 µ Not Used Same 19 µ Not Used Same 1A R/W Common Control 2 Bit Difference 1B R/W Common Control 3 Bit Difference 1C R/W Transmit Sa Bit Control Same 1D R/W Common Control 6 Same 1E R Synchronizer Status Same 1F R Receive Nonalign Frame Same 20 R/W Transmit Align Frame Same 21 R/W Transmit Nonalign Frame Same 22 R/W Transmit Channel Blocking 1 Same 23 R/W Transmit Channel Blocking 2 Same 24 R/W Transmit Channel Blocking 3 Same 25 R/W Transmit Channel Blocking 4 Same 26 R/W Transmit Idle 1 Same 27 R/W Transmit Idle 2 Same 28 R/W Transmit Idle 3 Same 29 R/W Transmit Idle 4 Same 2A R/W Transmit Idle Definition Same 2B R/W Receive Channel Blocking 1 Same 2C R/W Receive Channel Blocking 2 Same 2D R/W Receive Channel Blocking 3 Same 2E R/W Receive Channel Blocking 4 Same 2F R Receive Align Frame Same 30 R Receive Signaling 1 Same 31 R Receive Signaling 2 Same 32 R Receive Signaling 3 Same 33 R Receive Signaling 4 Same 34 R Receive Signaling 5 Same 35 R Receive Signaling 6 Same 36 R Receive Signaling 7 Same 37 R Receive Signaling 8 Same 38 R Receive Signaling 9 Same 39 R Receive Signaling 10 Same 3A R Receive Signaling 11 Same 3B R Receive Signaling 12 Same 3C R Receive Signaling 13 Same 3D R Receive Signaling 14 Same 3E R Receive Signaling 15 Same 3F R Receive Signaling 16 Same 40 R/W Transmit Signaling 1 Same 41 R/W Transmit Signaling 2 Same 42 R/W Transmit Signaling 3 Same 43 R/W Transmit Signaling 4 Same 44 R/W Transmit Signaling 5 Same 45 R/W Transmit Signaling 6 Same 46 R/W Transmit Signaling 7 Same 47 R/W Transmit Signaling 8 Same 48 R/W Transmit Signaling 9 Same 49 R/W Transmit Signaling 10 Same 4A R/W Transmit Signaling 11 Same 4B R/W Transmit Signaling 12 Same 4C R/W Transmit Signaling 13 Same 4D R/W Transmit Signaling 14 Same 4E R/W Transmit Signaling 15 Same 4F R/W Transmit Signaling 16 Same 50 R/W Transmit Si Bits Align Frame Same 51 R/W Transmit Si Bits Non-Align Frame Same 52 R/W Transmit Remote Alarm Bits Same 53 R/W Transmit Sa4 Bits Same 54 R/W Transmit Sa5 Bits Same 55 R/W Transmit Sa6 Bits Same 56 R/W Transmit Sa7 Bits Same 57 R/W Transmit Sa8 Bits Same 58 R Receive Si bits Align Frame Same 59 R Receive Si bits Nonalign Frame Same 5A R Receive Remote Alarm Bits Same 5B R Receive Sa4 Bits Same 5C R Receive Sa5 Bits Same 5D R Receive Sa6 Bits Same 5E R Receive Sa7 Bits Same 5F R Receive Sa8 Bits Same 63 R/W Transmit Channel 4 Not Used 64 R/W Transmit Channel 5 Not Used 65 R/W Transmit Channel 6 Not Used 66 R/W Transmit Channel 7 Not Used 67 R/W Transmit Channel 8 Not Used 68 R/W Transmit Channel 9 Not Used 69 R/W Transmit Channel 10 Not Used 6A R/W Transmit Channel 11 Not Used 6B R/W Transmit Channel 12 Not Used 6C R/W Transmit Channel 13 Not Used 6D R/W Transmit Channel 14 Not Used 6E R/W Transmit Channel 15 Not Used 6F R/W Transmit Channel 16 Not Used 70 R/W Transmit Channel 17 Not Used 71 R/W Transmit Channel 18 Not Used 72 R/W Transmit Channel 19 Not Used 73 R/W Transmit Channel 20 Not Used 74 R/W Transmit Channel 21 Not Used 75 R/W Transmit Channel 22 Not Used 76 R/W Transmit Channel 23 Not Used 77 R/W Transmit Channel 24 Not Used 78 R/W Transmit Channel 25 Not Used 79 R/W Transmit Channel 26 Not Used 7A R/W Transmit Channel 27 Not Used 7B R/W Transmit Channel 28 Not Used 7C R/W Transmit Channel 29 Not Used 7D R/W Transmit Channel 30 Not Used 7E R/W Transmit Channel 31 Not Used 7F R/W Transmit Channel 32 Not Used 80 R/W Receive Channel 1 Not Used 81 R/W Receive Channel 2 Not Used 82 R/W Receive Channel 3 Not Used 83 R/W Receive Channel 4 Not Used 84 R/W Receive Channel 5 Not Used 85 R/W Receive Channel 6 Not Used 86 R/W Receive Channel 7 Not Used 87 R/W Receive Channel 8 Not Used 88 R/W Receive Channel 9 Not Used 89 R/W Receive Channel 10 Not Used 8A R/W Receive Channel 11 Not Used 8B R/W Receive Channel 12 Not Used 9C R/W Receive Channel 13 Not Used 8D R/W Receive Channel 14 Not Used 8E R/W Receive Channel 15 Not Used 8F R/W Receive Channel 16 Not Used 90 R/W Receive Channel 17 Not Used 91 R/W Receive Channel 18 Not Used 92 R/W Receive Channel 19 Not Used 93 R/W Receive Channel 20 Not Used 94 R/W Receive Channel 21 Not Used 95 R/W Receive Channel 22 Not Used 96 R/W Receive Channel 23 Not Used 97 R/W Receive Channel 24 Not Used 98 R/W Receive Channel 25 Not Used 99 R/W Receive Channel 26 Not Used 9A R/W Receive Channel 27 Not Used 9B R/W Receive Channel 28 Not Used 9C R/W Receive Channel 29 Not Used 9D R/W Receive Channel 30 Not Used 9E R/W Receive Channel 31 Not Used 9F R/W Receive Channel 32 Not Used A0 R/W Transmit Channel Control 1 Not Used A1 R/W Transmit Channel Control 2 Not Used A2 R/W Transmit Channel Control 3 Not Used A3 R/W Transmit Channel Control 4 Not Used A4 R/W Receive Channel Control 1 Not Used A5 R/W Receive Channel Control 2 Not Used A6 R/W Receive Channel Control 3 Not Used A7 R/W Receive Channel Control 4 Not Used A8 R/W Common Control 4 Not Used A9 R Transmit DS0 Monitor Not Used AA R/W Common Control 5 Not Used AB R Receive DS0 Monitor Not Used AC R/W Test 3 Not Used AD µ Not Used Not Used AE µ Not Used Not Used AF µ Not Used Not Used B0 R/W HDLC Control Register Not Used B1 R/W HDLC Status Register Not Used B2 R/W HDLC Interrupt Mask Register Not Used B3 R/W Receive HDLC Information Register Not Used B4 R/W Receive HDLC FIFO Register Not Used B5 R/W Interleave Bus Operation Register Not Used B6 R/W Transmit HDLC Information Register Not Used B7 R/W Transmit HDLC FIFO Register Not Used B8 R/W Receive HDLC DS0 Control Register 1 Not Used B9 R/W Receive HDLC DS0 Control Register 2 Not Used BA R/W Transmit HDLC DS0 Control Register 1 Not Used BB R/W Transmit HDLC DS0 Control Register 2 Not Used BC µ Not Used Not Used BD µ Not Used Not Used BE µ Not Used Not Used BF µ Not Used Not Used Note: Test Registers 1 and 2 are used only by the factory; these registers must be cleared (set to all 0s) on power-up initialization to ensure proper operation. New Feature Register Usage Highlights specific registers containing bit locations related to new features. Each item can be found in the data sheet under the listed sections. Device Identification (Section 6) Register Function IDR Device Identification Register Expanded Elastic Stores Reset Functions (Section 6) Register Function CCR5 Common Control Register 5 CCR6 Common Control Register 6 Interrupt on Change of Signaling State (Section 7 and 10) Register Function SR1 Status Register 2 (bits 7 and 5) IMR1 Interrupt Mask Register 2 (bits 7 and 5) DS0 Monitoring (Section 6 and 9) Register Function CCR4 Common Control 4 (bits 4-0) CCR5 Common Control 5 (bits 4-0) TDSOM Transmit DS0 Monitor RDSOM Receive DS0 Monitor Hardware Based Signaling (Section 6 and 10.2) Register Function TCBR1-3 Transmit Channel Block Registers 1-3 CCR3 Common Control 3 (bits 3, 2) Signaling Freeze (Section 6 and 10.2) Register Function CCR2 Common Control 2 (bits 1, 0) Per Channel Loopback (Section 6 and 11.1) Register Function CCR3 Common Control 3 (bit 5) TIR1-3* Transmit Idle Register 1-3 * Alternate function for existing register set. Per Channel Code (Idle) Insertion (Section 11.1 and 11.2) Register Function TCC1-TCC4 Transmit Channel Control 1-4 TC1-TC32 Transmit Channels Registers 1-32 RCC1-RCC4 Receive Channel Control 1-4 RC1-RC32 Receive Channels Registers 1-32 Full HDLC and BOC Controller for FDL Support (Section 15) Register Function HCR HDLC Control Register HSR HDLC Status Register HIMR HDLC Interrupt Mask Register RHIR Receive HDLC Information Register RHFR Receive HDLC FIFO Register RDC1 Receive HDLC DS0 Control Register 1 RDC2 Receive HDLC DS0 Control Register 2 THIR Transmit HDLC Information Register THFR Transmit HDLC FIFO Register TDC1 Transmit HDLC DS0 Control Register 1 TDC2 Transmit HDLC DS0 Control Register 2 Interleaved PCM Bus Operation (Section 16) Register Function IBO Interleave Bus Operation Bit Assignment Changes Within Existing Registers Highlights bit locations in the DS21Q44 that have changed from the DS21Q43A. Register Bit # DS21Q43A Symbol DS21Q43A Description DS21Q44A Symbol DS21Q44A Description CCR2 0 N/A Not Assigned RFE Receive Freeze Enable CCR2 1 N/A Not Assigned RFF Receive Force Freeze CCR3 0 N/A Not Assigned RCLA Receive Carrier Loss Alternate Criteria CCR3 2 N/A Not Assigned THSE Transmit Side Hardware Signaling Insertion Enable CCR3 3 N/A Not Assigned RSRE Receive Side Signaling Reinsertion Enable CCR3 4 ESR Elastic Stores Reset N/A Not Assigned ISR 0 F3SR2 Status of Interrupt for SR2 in Framer 3 F3HDLC Framer 3 HDLC Controller Interrupt Request ISR 1 F3SR1 Status of Interrupt for SR1 in Framer 3 F3SR Framer 3 SR1 or SR2 Interrupt Request ISR 2 F2SR2 Status of Interrupt for SR2 in Framer 2 F2HDLC Framer 3 HDLC Controller Interrupt Request ISR 3 F2SR1 Status of Interrupt for SR1 in Framer 2 F2SR Framer 3 SR1 or SR2 Interrupt Request ISR 4 F1SR2 Status of Interrupt for SR2 in Framer 1 F1HDLC Framer 3 HDLC Controller Interrupt Request ISR 5 F1SR1 Status of Interrupt for SR1 in Framer 1 F1SR Framer 3 SR1 or SR2 Interrupt Request ISR 6 F0SR2 Status of Interrupt for SR2 in Framer 0 F0HDLC Framer 3 HDLC Controller Interrupt Request ISR 7 F0SR1 Status of Interrupt for SR1 in Framer 0 F0SR Framer 3 SR1 or SR2 Interrupt Request RIR 5 LORC Loss-of-Receive Clock N/A Not Assigned SR1 5 RSA1 Receive Signaling All 1s RSA1 Receive Signaling All 1s/Signaling Change SR1 7 RSA0 Receive Signaling All 0s RSA0 Receive Signaling All 0s/Signaling Change IMR1 5 RSA1 Receive Signaling All 1s RSA1 Receive Signaling All 1s/Signaling Change IMR1 7 RSA0 Receive Signaling All 0s RSA0 Receive Signaling All 0s/Signaling Change Register Bit Moves Function DS21Q43A Location DS21Q44 Location ESR CCR3.4 Split into RESR (CCR6.1) and TESR (CCR6.0) Register Address Moves Function DS21Q43A Location DS21Q44 Location ISR Any address between 60h to 7Fh or between E0h and FFh Any address from C0h to FFh Changes In Device Pinout Package Types The DS21Q43A and DS21Q44 are both offered in a 128 pin 20 x 14 x 1.4 mm TQFP. Values listed are for body dimensions. Device Pin Differences Note: Brackets [ ] indicate pin function when the DS21Q44 is configured for emulation of the DS21Q43A (FMS = 1). Control Port Pins DS21Q44 DS21Q43A Function A7 VSS Address Bus Bit 7 FMS VDD Framer Mode Select CLKSI [RLOS/LOTC3] RLOS/LOTC3 8MHz Clock Reference Input [Receive Loss-of-Sync/Loss-of-Transmit Clock from Framer 3] 8MCLK [RMSYNC3] RMSYNC3 8MHz Clock [Receive Multiframe Sync from Framer 3] Transmit Side Digital Pins DS21Q44 DS21Q43A Function TSIG0 [TCHCLK0] TCHCLK0 Transmit Signaling Input for Framer 0 [Transmit Channel Clock from Framer 0] TSIG1 [TCHCLK1] TCHCLK1 Transmit Signaling Input for Framer 1 [Transmit Channel Clock from Framer 1] TSIG2 [TCHCLK2] TCHCLK2 Transmit Signaling Input for Framer 2 [Transmit Channel Clock from Framer 2] TSIG3 [TCHCLK3] TCHCLK3 Transmit Signaling Input for Framer 3 [Transmit Channel Clock from Framer 3] Receive Side Digital/JTAG Pins DS21Q44 DS21Q43A Function JTRST* [RLOS/LOTC0] RLOS/LOTC0 JTAG Reset [Receive Loss-of-Sync/Loss-of-Transmit Clock from Framer 0] JTCLK [RLOS/LOTC1] RLOS/LOTC1 JTAG Test Clock [Receive Loss-of-Sync/Loss-of-Transmit Clock from Framer 1] JTDO [RLOS/LOTC2] RLOS/LOTC2 JTAG Test Data Output [Receive Loss-of-Sync/Loss-of-Transmit Clock from Framer 2] CLKSI [RLOS/LOTC3] RLOS/LOTC3 8MHz Clock [Receive Loss-of-Sync/Loss-of-Transmit Clock from Framer 3] SPARE1 [RMSYNC0] RMSYNC0 Reserved. Must be left unconnected for normal operation [Receive Multiframe Sync from Framer 0] JTMS [RMSYNC1] RMSYNC1 JTAG Test Mode Select [Receive Multiframe Sync from Framer 1] JTDI [RMSYNC2] RMSYNC2 JTAG Test Data Input [Receive Multiframe Sync from Framer 2] 8MCLK [RMSYNC3] RMSYNC3 MCLK Clock Reference Input [Receive Multiframe Sync from Framer 3] RSIG0 [RCHCLK0] RCHCLK0 Receive Signaling Output from Framer 0 [Receive Channel Clock from Framer 0] RSIG0 [RCHCLK1] RCHCLK1 Receive Signaling Output from Framer 1 [Receive Channel Clock from Framer 1] RSIG0 [RCHCLK2] RCHCLK2 Receive Signaling Output from Framer 2 [Receive Channel Clock from Framer 2] RSIG0 [RCHCLK3] RCHCLK3 Receive Signaling Output from Framer 3 [Receive Channel Clock from Framer 3] Operating the DS21Q44 in DS21Q43A Emulation Mode The DS21Q44 is a superset of the DS21Q43A and can be configured to emulate the latter. This mode is enabled by tying the framer mode select (FMS) pin to VCC. Because the DS21Q44 supports an expanded register set, the A7 address pin was added to the device. Although the DS21Q44 does not require the functionality associated with the additional registers when in DS21Q43A emulation mode, the A7 pin must be used. This is necessary because the device does not automatically clear its register space on power-up. After the supplies are stable, each of four framers register space should be configured for operation by writing to all of the internal registers. This can be accomplished in a two-pass approach on each framer. Clear framers register space by writing 00h to the addresses 00h through BFh. Program required registers to achieve desired operating mode. We Want Your Feedback! Automatic Updates Would you like to be automatically notified when new application notes are published in your areas of interest? Sign up for EE-Mail™. More Information   APP 356: Mar 29, 2001 DS21Q43A Quad E1 Framer Full Data Sheet (PDF, 760kB) DS21Q44 Enhanced Quad E1 Framer Full Data Sheet (PDF, 712kB) Free Samples   Download, PDF Format (192kB)  AN356, AN 356, APP356, Appnote356, Appnote 356