Embedded Peripherals IP User Guide

ID 683130
Date 8/11/2025
Public
Document Table of Contents
1. Introduction 2. Avalon® -ST Single-Clock and Dual-Clock FIFO Cores 3. Avalon® -ST Serial Peripheral Interface Core 4. SPI Core 5. SPI Agent/JTAG to Avalon® Host Bridge Cores 6. Intel eSPI Agent Core 7. eSPI to LPC Bridge Core 8. Ethernet MDIO Core 9. Intel FPGA 16550 Compatible UART Core 10. UART Core 11. JTAG UART Core 12. Intel FPGA Avalon® Mailbox Core 13. Intel FPGA Avalon® Mutex Core 14. Intel FPGA Avalon® I2C (Host) Core 15. Intel FPGA I2C Agent to Avalon® -MM Host Bridge Core 16. Intel FPGA Avalon® Compact Flash Core 17. EPCS/EPCQA Serial Flash Controller Core 18. Intel FPGA Serial Flash Controller Core 19. Intel FPGA Serial Flash Controller II Core 20. Intel FPGA Generic QUAD SPI Controller Core 21. Intel FPGA Generic QUAD SPI Controller II Core 22. Interval Timer Core 23. Intel FPGA Avalon FIFO Memory Core 24. On-Chip Memory (RAM and ROM) Intel FPGA IP 25. On-Chip Memory II (RAM or ROM) Intel FPGA IP 26. Optrex 16207 LCD Controller Core 27. PIO Core 28. PLL Cores 29. DMA Controller Core 30. Modular Scatter-Gather DMA Core 31. Scatter-Gather DMA Controller Core 32. SDRAM Controller Core 33. Tri-State SDRAM Core 34. Video Sync Generator and Pixel Converter Cores 35. Intel FPGA Interrupt Latency Counter Core 36. Performance Counter Unit Core 37. Vectored Interrupt Controller Core 38. Avalon® -ST Data Pattern Generator and Checker Cores 39. Avalon® -ST Test Pattern Generator and Checker Cores 40. System ID Peripheral Core 41. Avalon® Packets to Transactions Converter Core 42. Avalon® -ST Multiplexer and Demultiplexer Cores 43. Avalon® -ST Bytes to Packets and Packets to Bytes Converter IP 44. Avalon® -ST Delay Core 45. Avalon® -ST Round Robin Scheduler Core 46. Avalon® -ST Splitter Core 47. Avalon® -MM DDR Memory Half Rate Bridge Core 48. Intel FPGA GMII to RGMII Converter Core 49. HPS GMII to RGMII Adapter Intel® FPGA IP 50. Intel FPGA MII to RMII Converter Core 51. HPS GMII to TSE 1000BASE-X/SGMII PCS Bridge Core Intel® FPGA IP 52. Intel FPGA HPS EMAC to Multi-rate PHY GMII Adapter Core 53. Intel FPGA MSI to GIC Generator Core 54. Cache Coherency Translator Intel® FPGA IP 55. Altera ACE5-Lite Cache Coherency Translator 56. Lightweight UART Core

9.4.8. msr

Identifier Title Offset Access Reset Value Description
msr Modem Status Register 0x18 R 0x00000000 It should be noted that whenever bits 0, 1, 2 or 3 are set to logic one, to indicate a change on the modem control inputs, a modem status interrupt will be generated if enabled via the IER regardless of when the change occurred. Since the delta bits (bits 0, 1, 3) can get set after a reset if their respective modem signals are active (see individual bits for details), a read of the MSR after reset can be performed to prevent unwanted interrupts.
Bit Fields
31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16
15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
dcd ri dsr cts ddcd teri ddsr dcts
Table 79.  msr Fields
Bit Name/Identifier Description Access Reset
[31:8] Reserved R 0x0
[7] Data Carrier Detect (dcd)

This bit is the complement of the modem control line (dcd_n). This bit is used to indicate the current state of dcd_n. When the Data Carrier Detect input (dcd_n) is asserted it is an indication that the carrier has been detected by the modem or data set.

R 0x0
[6] Ring Indicator (ri)

This bit is the complement of modem control line (ri_n). This bit is used to indicate the current state of ri_n. When the Ring Indicator input (ri_n) is asserted it is an indication that a telephone ringing signal has been received by the modem or data set.

R 0x0
[5] Data Set Ready (dsr)

This bit is the complement of modem control line dsr_n. This bit is used to indicate the current state of dsr_n. When the Data Set Ready input (dsr_n) is asserted it is an indication that the modem or data set is ready to establish communications with the uart.

R 0x0
[4] Clear to Send (cts)

This bit is the complement of modem control line cts_n. This bit is used to indicate the current state of cts_n. When the Clear to Send input (cts_n) is asserted it is an indication that the modem or data set is ready to exchange data with the uart.

R 0x0
[3] Delta Data Carrier Detect (ddcd)

This is used to indicate that the modem control line dcd_n has changed since the last time the MSR was read. Reading the MSR clears the DDCD bit.

Note: If the DDCD bit is not set and the dcd_n signal is asserted (low) and a reset occurs (software or otherwise), then the DDCD bit will get set when the reset is removed if the dcd_n signal remains asserted.
RC 0x0
[2] Trailing Edge of Ring Indicator (teri)

This is used to indicate that a change on the input ri_n (from an active low, to an inactive high state) has occurred since the last time the MSR was read. Reading the MSR clears the TERI bit.

RC 0x0
[1] Delta Data Set Ready (ddsr)

This is used to indicate that the modem control line dsr_n has changed since the last time the MSR was read. Reading the MSR clears the DDSR bit.

Note: If the DDSR bit is not set and the dsr_n signal is asserted (low) and a reset occurs (software or otherwise), then the DDSR bit will get set when the reset is removed if the dsr_n signal remains asserted.
RC 0x0
[0] Delta Clear to Send (dcts)

This is used to indicate that the modem control line cts_n has changed since the last time the MSR was read. Reading the MSR clears the DCTS bit.

Note: If the DCTS bit is not set and the cts_n signal is asserted (low) and a reset occurs (software or otherwise), then the DCTS bit will get set when the reset is removed if the cts_n signal remains asserted.
RC 0x0