Name | Offset | Length | Description |
---|---|---|---|
spi_host.INTR_STATE |
0x0 | 4 | Interrupt State Register |
spi_host.INTR_ENABLE |
0x4 | 4 | Interrupt Enable Register |
spi_host.INTR_TEST |
0x8 | 4 | Interrupt Test Register |
spi_host.ALERT_TEST |
0xc | 4 | Alert Test Register |
spi_host.CONTROL |
0x10 | 4 | Control register |
spi_host.STATUS |
0x14 | 4 | Status register |
spi_host.CONFIGOPTS |
0x18 | 4 | Configuration options register. |
spi_host.CSID |
0x1c | 4 | Chip-Select ID |
spi_host.COMMAND |
0x20 | 4 | Command Register |
spi_host.RXDATA |
0x24 | 4 | SPI Receive Data. |
spi_host.TXDATA |
0x28 | 4 | SPI Transmit Data. |
spi_host.ERROR_ENABLE |
0x2c | 4 | Controls which classes of errors raise an interrupt. |
spi_host.ERROR_STATUS |
0x30 | 4 | Indicates that any errors that have occurred. |
spi_host.EVENT_ENABLE |
0x34 | 4 | Controls which classes of SPI events raise an interrupt. |
Interrupt State Register
- Offset:
0x0
- Reset default:
0x0
- Reset mask:
0x3
{"reg": [{"name": "error", "bits": 1, "attr": ["rw1c"], "rotate": -90}, {"name": "spi_event", "bits": 1, "attr": ["ro"], "rotate": -90}, {"bits": 30}], "config": {"lanes": 1, "fontsize": 10, "vspace": 110}}
Bits | Type | Reset | Name | Description |
---|---|---|---|---|
31:2 | Reserved | |||
1 | ro | 0x0 | spi_event | Event-related interrupts, see EVENT_ENABLE register for more information. |
0 | rw1c | 0x0 | error | Error-related interrupts, see ERROR_ENABLE register for more information. |
Interrupt Enable Register
- Offset:
0x4
- Reset default:
0x0
- Reset mask:
0x3
{"reg": [{"name": "error", "bits": 1, "attr": ["rw"], "rotate": -90}, {"name": "spi_event", "bits": 1, "attr": ["rw"], "rotate": -90}, {"bits": 30}], "config": {"lanes": 1, "fontsize": 10, "vspace": 110}}
Bits | Type | Reset | Name | Description |
---|---|---|---|---|
31:2 | Reserved | |||
1 | rw | 0x0 | spi_event | Enable interrupt when INTR_STATE.spi_event is set. |
0 | rw | 0x0 | error | Enable interrupt when INTR_STATE.error is set. |
Interrupt Test Register
- Offset:
0x8
- Reset default:
0x0
- Reset mask:
0x3
{"reg": [{"name": "error", "bits": 1, "attr": ["wo"], "rotate": -90}, {"name": "spi_event", "bits": 1, "attr": ["wo"], "rotate": -90}, {"bits": 30}], "config": {"lanes": 1, "fontsize": 10, "vspace": 110}}
Bits | Type | Reset | Name | Description |
---|---|---|---|---|
31:2 | Reserved | |||
1 | wo | 0x0 | spi_event | Write 1 to force INTR_STATE.spi_event to 1. |
0 | wo | 0x0 | error | Write 1 to force INTR_STATE.error to 1. |
Alert Test Register
- Offset:
0xc
- Reset default:
0x0
- Reset mask:
0x1
{"reg": [{"name": "fatal_fault", "bits": 1, "attr": ["wo"], "rotate": -90}, {"bits": 31}], "config": {"lanes": 1, "fontsize": 10, "vspace": 130}}
Bits | Type | Reset | Name | Description |
---|---|---|---|---|
31:1 | Reserved | |||
0 | wo | 0x0 | fatal_fault | Write 1 to trigger one alert event of this kind. |
Control register
- Offset:
0x10
- Reset default:
0x7f
- Reset mask:
0xe000ffff
{"reg": [{"name": "RX_WATERMARK", "bits": 8, "attr": ["rw"], "rotate": 0}, {"name": "TX_WATERMARK", "bits": 8, "attr": ["rw"], "rotate": 0}, {"bits": 13}, {"name": "OUTPUT_EN", "bits": 1, "attr": ["rw"], "rotate": -90}, {"name": "SW_RST", "bits": 1, "attr": ["rw"], "rotate": -90}, {"name": "SPIEN", "bits": 1, "attr": ["rw"], "rotate": -90}], "config": {"lanes": 1, "fontsize": 10, "vspace": 110}}
Bits | Type | Reset | Name |
---|---|---|---|
31 | rw | 0x0 | SPIEN |
30 | rw | 0x0 | SW_RST |
29 | rw | 0x0 | OUTPUT_EN |
28:16 | Reserved | ||
15:8 | rw | 0x0 | TX_WATERMARK |
7:0 | rw | 0x7f | RX_WATERMARK |
Enables the SPI host. On reset, this field is 0, meaning that no transactions can proceed.
Clears the internal state (not registers) to the reset state when set to 1, including the FIFOs, the CDC's, the core state machine and the shift register. In the current implementation, the CDC FIFOs are drained not reset. Therefore software must confirm that both FIFO's empty before releasing the IP from reset.
Enable the SPI host output buffers for the sck, csb, and sd lines. This allows the SPI_HOST IP to connect to the same bus as other SPI controllers without interference.
If EVENT_ENABLE.TXWM
is set, the IP will send
an interrupt when the depth of the TX FIFO drops below
TX_WATERMARK words (32b each).
If EVENT_ENABLE.RXWM
is set, the IP will send
an interrupt when the depth of the RX FIFO reaches
RX_WATERMARK words (32b each).
Status register
- Offset:
0x14
- Reset default:
0x0
- Reset mask:
0xffdfffff
{"reg": [{"name": "TXQD", "bits": 8, "attr": ["ro"], "rotate": 0}, {"name": "RXQD", "bits": 8, "attr": ["ro"], "rotate": 0}, {"name": "CMDQD", "bits": 4, "attr": ["ro"], "rotate": 0}, {"name": "RXWM", "bits": 1, "attr": ["ro"], "rotate": -90}, {"bits": 1}, {"name": "BYTEORDER", "bits": 1, "attr": ["ro"], "rotate": -90}, {"name": "RXSTALL", "bits": 1, "attr": ["ro"], "rotate": -90}, {"name": "RXEMPTY", "bits": 1, "attr": ["ro"], "rotate": -90}, {"name": "RXFULL", "bits": 1, "attr": ["ro"], "rotate": -90}, {"name": "TXWM", "bits": 1, "attr": ["ro"], "rotate": -90}, {"name": "TXSTALL", "bits": 1, "attr": ["ro"], "rotate": -90}, {"name": "TXEMPTY", "bits": 1, "attr": ["ro"], "rotate": -90}, {"name": "TXFULL", "bits": 1, "attr": ["ro"], "rotate": -90}, {"name": "ACTIVE", "bits": 1, "attr": ["ro"], "rotate": -90}, {"name": "READY", "bits": 1, "attr": ["ro"], "rotate": -90}], "config": {"lanes": 1, "fontsize": 10, "vspace": 110}}
Bits | Type | Reset | Name | Description |
---|---|---|---|---|
31 | ro | 0x0 | READY | When high, indicates the SPI host is ready to receive commands. Writing to COMMAND when READY is low is an error, and will trigger an interrupt. |
30 | ro | 0x0 | ACTIVE | When high, indicates the SPI host is processing a previously issued command. |
29 | ro | 0x0 | TXFULL | When high, indicates that the transmit data fifo is full. Any further writes to TXDATA will create an error interrupt. |
28 | ro | 0x0 | TXEMPTY | When high, indicates that the transmit data fifo is empty. |
27 | ro | 0x0 | TXSTALL | If high, signifies that an ongoing transaction has stalled due to lack of data in the TX FIFO |
26 | ro | 0x0 | TXWM | If high, the amount of data in the TX FIFO has fallen below the level of CONTROL.TX_WATERMARK words (32b each). |
25 | ro | 0x0 | RXFULL | When high, indicates that the receive fifo is full. Any ongoing transactions will stall until firmware reads some data from RXDATA. |
24 | ro | 0x0 | RXEMPTY | When high, indicates that the receive fifo is empty. Any reads from RX FIFO will cause an error interrupt. |
23 | ro | 0x0 | RXSTALL | If high, signifies that an ongoing transaction has stalled due to lack of available space in the RX FIFO |
22 | ro | 0x0 | BYTEORDER | The value of the ByteOrder parameter, provided so that firmware can confirm proper IP configuration. |
21 | Reserved | |||
20 | ro | 0x0 | RXWM | If high, the number of 32-bits in the RX FIFO now exceeds the CONTROL.RX_WATERMARK entries (32b each). |
19:16 | ro | 0x0 | CMDQD | Command queue depth. Indicates how many unread 32-bit words are currently in the command segment queue. |
15:8 | ro | 0x0 | RXQD | Receive queue depth. Indicates how many unread 32-bit words are currently in the RX FIFO. When active, this result may an underestimate due to synchronization delays. |
7:0 | ro | 0x0 | TXQD | Transmit queue depth. Indicates how many unsent 32-bit words are currently in the TX FIFO. When active, this result may be an overestimate due to synchronization delays. |
Configuration options register.
Contains options for controlling each peripheral. One register per cs_n line
- Reset default:
0x0
- Reset mask:
0xefffffff
Name | Offset |
---|---|
CONFIGOPTS | 0x18 |
{"reg": [{"name": "CLKDIV", "bits": 16, "attr": ["rw"], "rotate": 0}, {"name": "CSNIDLE", "bits": 4, "attr": ["rw"], "rotate": -90}, {"name": "CSNTRAIL", "bits": 4, "attr": ["rw"], "rotate": -90}, {"name": "CSNLEAD", "bits": 4, "attr": ["rw"], "rotate": -90}, {"bits": 1}, {"name": "FULLCYC", "bits": 1, "attr": ["rw"], "rotate": -90}, {"name": "CPHA", "bits": 1, "attr": ["rw"], "rotate": -90}, {"name": "CPOL", "bits": 1, "attr": ["rw"], "rotate": -90}], "config": {"lanes": 1, "fontsize": 10, "vspace": 100}}
Bits | Type | Reset | Name |
---|---|---|---|
31 | rw | 0x0 | CPOL |
30 | rw | 0x0 | CPHA |
29 | rw | 0x0 | FULLCYC |
28 | Reserved | ||
27:24 | rw | 0x0 | CSNLEAD |
23:20 | rw | 0x0 | CSNTRAIL |
19:16 | rw | 0x0 | CSNIDLE |
15:0 | rw | 0x0 | CLKDIV |
The polarity of the sck clock signal. When CPOL is 0, sck is low when idle, and emits high pulses. When CPOL is 1, sck is high when idle, and emits a series of low pulses.
The phase of the sck clock signal relative to the data. When
CPHA = 0, the data changes on the trailing edge of sck
and is typically sampled on the leading edge. Conversely
if CPHA = 1 high, data lines change on the leading edge of
sck and are typically sampled on the trailing edge.
CPHA should be chosen to match the phase of the selected
device. The sampling behavior is modified by the
CONFIGOPTS.FULLCYC
bit.
Full cycle. Modifies the CPHA sampling behaviour to allow for longer device logic setup times. Rather than sampling the SD bus a half cycle after shifting out data, the data is sampled a full cycle after shifting data out. This means that if CPHA = 0, data is shifted out on the trailing edge, and sampled a full cycle later. If CPHA = 1, data is shifted and sampled with the trailing edge, also separated by a full cycle.
CS_N Leading Time. Indicates the number of half sck cycles, CSNLEAD+1, to leave between the falling edge of cs_n and the first edge of sck. Setting this register to zero corresponds to the minimum delay of one-half sck cycle
CS_N Trailing Time. Indicates the number of half sck cycles, CSNTRAIL+1, to leave between last edge of sck and the rising edge of cs_n. Setting this register to zero corresponds to the minimum delay of one-half sck cycle.
Minimum idle time between commands. Indicates the minimum number of sck half-cycles to hold cs_n high between commands. Setting this register to zero creates a minimally-wide CS_N-high pulse of one-half sck cycle.
Core clock divider. Slows down subsequent SPI transactions by a
factor of (CLKDIV+1) relative to the core clock frequency. The
period of sck, T(sck) then becomes 2*(CLK_DIV+1)*T(core)
Chip-Select ID
Controls which device to target with the next command. This register
is passed to the core whenever COMMAND
is written. The core then
asserts cio_csb_o[CSID
] during the execution of the command.
- Offset:
0x1c
- Reset default:
0x0
- Reset mask:
0xffffffff
{"reg": [{"name": "CSID", "bits": 32, "attr": ["rw"], "rotate": 0}], "config": {"lanes": 1, "fontsize": 10, "vspace": 80}}
Bits | Type | Reset | Name | Description |
---|---|---|---|---|
31:0 | rw | 0x0 | CSID | Chip Select ID |
Command Register
Parameters specific to each command segment. Unlike the CONFIGOPTS
multi-register,
there is only one command register for controlling all attached SPI devices
- Offset:
0x20
- Reset default:
0x0
- Reset mask:
0x3fff
{"reg": [{"name": "LEN", "bits": 9, "attr": ["wo"], "rotate": 0}, {"name": "CSAAT", "bits": 1, "attr": ["wo"], "rotate": -90}, {"name": "SPEED", "bits": 2, "attr": ["wo"], "rotate": -90}, {"name": "DIRECTION", "bits": 2, "attr": ["wo"], "rotate": -90}, {"bits": 18}], "config": {"lanes": 1, "fontsize": 10, "vspace": 110}}
Bits | Type | Reset | Name |
---|---|---|---|
31:14 | Reserved | ||
13:12 | wo | 0x0 | DIRECTION |
11:10 | wo | 0x0 | SPEED |
9 | wo | 0x0 | CSAAT |
8:0 | wo | 0x0 | LEN |
The direction for the following command: "0" = Dummy cycles (no TX/RX). "1" = Rx only, "2" = Tx only, "3" = Bidirectional Tx/Rx (Standard SPI mode only).
The speed for this command segment: "0" = Standard SPI. "1" = Dual SPI. "2"=Quad SPI, "3": RESERVED.
Chip Select Active After Transaction.
If COMMAND.CSAAT
= 0, the chip select line is raised immediately
at the end of the command segment.
If COMMAND.CSAAT
= 1, the chip select line is left low at the
end of the current transaction segment.
This allows the creation of longer, more complete SPI transactions,
consisting of several separate segments for issuing instructions,
pausing for dummy cycles, and transmitting or receiving data from
the device.
Segment Length.
For read or write segments, this field controls the
number of 1-byte bursts to transmit and or receive in
this command segment. The number of cyles required
to send or received a byte will depend on COMMAND.SPEED.
For dummy segments, (COMMAND.DIRECTION
== 0), this register
controls the number of dummy cycles to issue.
The number of bytes (or dummy cycles) in the segment will be
equal to COMMAND.LEN
+ 1.
SPI Receive Data.
Reads from this window pull data from the RXFIFO.
The serial order of bit transmission is chosen to match SPI flash devices. Individual bytes are always transmitted with the most significant bit first. Only four-byte reads are supported. If ByteOrder = 0, the first byte received is packed in the MSB of !!RXDATA. For some processor architectures, this could lead to shuffling of flash data as compared to how it is written in memory. In which case, choosing ByteOrder = 1 can reverse the byte-order of each data read, causing the first byte received to be packed into the LSB of !!RXDATA. (Though within each byte the most significant bit is always pulled from the bus first.)
- Word Aligned Offset Range:
0x24
to0x24
- Size (words):
1
- Access:
ro
- Byte writes are not supported.
SPI Transmit Data.
Data written to this window is placed into the TXFIFO. Byte-enables are supported for writes.
The serial order of bit transmission is chosen to match SPI flash devices. Individual bytes are always transmitted with the most significant bit first. Multi-byte writes are also supported, and if ByteOrder = 0, the bits of !!TXDATA are transmitted strictly in order of decreasing signficance (i.e. most signicant bit first). For some processor architectures, this could lead to shuffling of flash data as compared to how it is written in memory. In which case, choosing ByteOrder = 1 can reverse the byte-order of multi-byte data writes. (Though within each byte the most significant bit is always sent first.)
- Word Aligned Offset Range:
0x28
to0x28
- Size (words):
1
- Access:
wo
- Byte writes are supported.
Controls which classes of errors raise an interrupt.
- Offset:
0x2c
- Reset default:
0x1f
- Reset mask:
0x1f
{"reg": [{"name": "CMDBUSY", "bits": 1, "attr": ["rw"], "rotate": -90}, {"name": "OVERFLOW", "bits": 1, "attr": ["rw"], "rotate": -90}, {"name": "UNDERFLOW", "bits": 1, "attr": ["rw"], "rotate": -90}, {"name": "CMDINVAL", "bits": 1, "attr": ["rw"], "rotate": -90}, {"name": "CSIDINVAL", "bits": 1, "attr": ["rw"], "rotate": -90}, {"bits": 27}], "config": {"lanes": 1, "fontsize": 10, "vspace": 110}}
Bits | Type | Reset | Name | Description |
---|---|---|---|---|
31:5 | Reserved | |||
4 | rw | 0x1 | CSIDINVAL | Invalid CSID: If this bit is set, the block sends an error interrupt whenever a command is submitted, but CSID exceeds NumCS. |
3 | rw | 0x1 | CMDINVAL | Invalid Command Errors: If this bit is set, the block sends an error interrupt whenever a command is sent with invalid values for COMMAND.SPEED or COMMAND.DIRECTION. |
2 | rw | 0x1 | UNDERFLOW | Underflow Errors: If this bit is set, the block sends an error interrupt whenever there is a read from RXDATA but the RX FIFO is empty. |
1 | rw | 0x1 | OVERFLOW | Overflow Errors: If this bit is set, the block sends an error interrupt whenever the TX FIFO overflows. |
0 | rw | 0x1 | CMDBUSY | Command Error: If this bit is set, the block sends an error interrupt whenever a command is issued while busy (i.e. a 1 is when STATUS.READY is not asserted.) |
Indicates that any errors that have occurred. When an error occurs, the corresponding bit must be cleared here before issuing any further commands.
- Offset:
0x30
- Reset default:
0x0
- Reset mask:
0x3f
{"reg": [{"name": "CMDBUSY", "bits": 1, "attr": ["rw1c"], "rotate": -90}, {"name": "OVERFLOW", "bits": 1, "attr": ["rw1c"], "rotate": -90}, {"name": "UNDERFLOW", "bits": 1, "attr": ["rw1c"], "rotate": -90}, {"name": "CMDINVAL", "bits": 1, "attr": ["rw1c"], "rotate": -90}, {"name": "CSIDINVAL", "bits": 1, "attr": ["rw1c"], "rotate": -90}, {"name": "ACCESSINVAL", "bits": 1, "attr": ["rw1c"], "rotate": -90}, {"bits": 26}], "config": {"lanes": 1, "fontsize": 10, "vspace": 130}}
Bits | Type | Reset | Name | Description |
---|---|---|---|---|
31:6 | Reserved | |||
5 | rw1c | 0x0 | ACCESSINVAL | Indicates that TLUL attempted to write to TXDATA with no bytes enabled. Such 'zero byte' writes are not supported. |
4 | rw1c | 0x0 | CSIDINVAL | Indicates a command was attempted with an invalid value for CSID. |
3 | rw1c | 0x0 | CMDINVAL | Indicates an invalid command segment, meaning either an invalid value of COMMAND.SPEED or a request for bidirectional data transfer at dual or quad speed |
2 | rw1c | 0x0 | UNDERFLOW | Indicates that firmware has attempted to read from RXDATA when the RX FIFO is empty. |
1 | rw1c | 0x0 | OVERFLOW | Indicates that firmware has overflowed the TX FIFO |
0 | rw1c | 0x0 | CMDBUSY | Indicates a write to COMMAND when STATUS.READY = 0. |
Controls which classes of SPI events raise an interrupt.
- Offset:
0x34
- Reset default:
0x0
- Reset mask:
0x3f
{"reg": [{"name": "RXFULL", "bits": 1, "attr": ["rw"], "rotate": -90}, {"name": "TXEMPTY", "bits": 1, "attr": ["rw"], "rotate": -90}, {"name": "RXWM", "bits": 1, "attr": ["rw"], "rotate": -90}, {"name": "TXWM", "bits": 1, "attr": ["rw"], "rotate": -90}, {"name": "READY", "bits": 1, "attr": ["rw"], "rotate": -90}, {"name": "IDLE", "bits": 1, "attr": ["rw"], "rotate": -90}, {"bits": 26}], "config": {"lanes": 1, "fontsize": 10, "vspace": 90}}
Bits | Type | Reset | Name |
---|---|---|---|
31:6 | Reserved | ||
5 | rw | 0x0 | IDLE |
4 | rw | 0x0 | READY |
3 | rw | 0x0 | TXWM |
2 | rw | 0x0 | RXWM |
1 | rw | 0x0 | TXEMPTY |
0 | rw | 0x0 | RXFULL |
Assert to send a spi_event interrupt whenever STATUS.ACTIVE
goes low
Assert to send a spi_event interrupt whenever STATUS.READY
goes high
Assert to send a spi_event interrupt whenever the number of 32-bit words in
the TX FIFO is less than CONTROL.TX_WATERMARK.
To prevent the
reassertion of this interrupt add more data to the TX FIFO, or
reduce CONTROL.TX_WATERMARK.
Assert to send a spi_event interrupt whenever the number of 32-bit words in
the RX FIFO is greater than CONTROL.RX_WATERMARK.
To prevent the
reassertion of this interrupt, read more data from the RX FIFO, or
increase CONTROL.RX_WATERMARK.
Assert to send a spi_event interrupt whenever STATUS.TXEMPTY
goes high
Assert to send a spi_event interrupt whenever STATUS.RXFULL
goes high