====== IP Core: GECKO3COM simple ======
FIXME
This is the documentation about the GECKO3COM simple IP core which is meant to be used in FPGA designs **without** an embedded processor. If you plan to build a microblaze based FPGA design use the [[:gecko-systems:gecko3com:ip_gecko3com_plb|GECKO3COM plb]] IP core.

===== Usage =====
{{ :gecko-systems:gecko3com:gecko3com_simple_symbol.png?direct&300 |GECKO3COM simple symbol}}

==== Port description ====

^ Generic name ^ Type ^ Default Value ^ Description ^
| BUSWIDTH | integer | 32  | Vector size of the FIFO databuses |

^ Port name ^ Direction ^ Type ^ Description ^
| i_nReset | in | std_logic| Low-active, asynchronous reset |
| i_sysclk | in | std_logic| FPGA System Clock |
| ||||
| i_receive_fifo_rd_en | in | std_logic| Receive FIFO read enable signal. //o_receive_fifo_data// will we valid one clock cycle after the read enable is activated |
| o_receive_fifo_empty | out | std_logic| Receive FIFO empty signal |
| o_receive_fifo_data  | out | std_logic_vector(BUSWIDTH-1 downto 0)| Receive FIFO data |
| o_receive_transfersize | out | std_logic_vector(31 downto 0)| Transfer length read from the TMC header.\\ The host will write this number of **bytes** to the device |
| o_receive_end_of_message | out | std_logic| All data expected to be received is available in the receive FIFO |
| o_receive_newdata | out | std_logic| A new valid OUT transfer header was detected. The //o_receive_transfersize// value is valid and new data will be available in the receive FIFO |
| ||||
| i_send_fifo_wr_en | in | std_logic | Send FIFO write enable signal. The FIFO will store the data on the next rising edge of //i_sysclk// |
| o_send_fifo_full | out | std_logic | Send FIFO full signal |
| i_send_fifo_data | in | std_logic_vector(BUSWIDTH-1 downto 0) | Send FIFO data |
| i_send_transfersize | in | std_logic_vector(31 downto 0) | Number of **bytes** of the response data to be sent to the host. It must be lower or equal //o_receive_transfersize// |
| i_send_transfersize_en | in | std_logic | Send transfer size write enable signal. The //i_send_transfersize// value will be stored on the next rising edge of //i_sysclk//. This also signals to the IP core that data is ready to be sent to the host |
| i_send_have_more_data | in | std_logic | Set this signal if there is more data to be sent to the host than the maximum number of bytes requested by the host (Response data length greater than //o_receive_transfersize//) |
| o_send_data_request | out | std_logic | The host has requested data from the device. The //o_receive_transfersize// value is valid (This is the maximum allowed number of bytes to be sent). The core is waiting for data in the send FIFO and that a valid value is written to //i_send_transfersize// |
| o_send_finished | out | std_logic | Signals that the core is finished sending data to the host |
| ||||
| o_rx | out | std_logic | Receiving data signalization|
| o_tx | out | std_logic | Transmitting data signalization|
| ||||
| **Interface signals to the EZ-USB FX2** ||||
| i_IFCLK| in | std_logic | GPIF CLK (GPIF is Master and provides the clock)|
| i_WRU | in | std_logic | Write request from GPIF |
| i_RDYU | in | std_logic | GPIF is ready |
| o_WRX | out | std_logic | Request to write to the GPIF|
| o_RDYX | out | std_logic | FPGA is ready |
| b_gpif_bus | inout | std_logic_vector(SIZE_DBUS_GPIF-1 downto 0) | Bidirectional data bus|


==== Logic utilization ====

This numbers show the logic utilization of the whole GECKO3COM_simple_test project which includes a bit more logic elements than the GECKO3COM simple IP core alone.

^ Resource Type ^ Used ^ Available (Spartan3 4000) ^ Utilization ^
| Number of Slice Flip Flops | 909 | 55,296 | 1% |
| Number of occupied Slices | 804 | 27,648 | 2% |
| Total Number of 4 input LUTs | 1,137 | 55,296 | 2% |
| Number of bonded IOBs | 30 | 489 | 6% |
| Number of RAMB16s | 4 | 96 | 4% |
| Number of BUFGMUXs | 2 | 8 | 25% |

===== Internal structure =====

{{ :gecko-systems:gecko3com:gecko3com_simple_structure.png?direct&500 |}}