Altera CPRI IP Core - Manual (Page 137)

Chapter 7: Software Interface 7–21
MAP Interface and AUX Interface Configuration Registers
December 2013 Altera Corporation CPRI MegaCore Function
User Guide
Table 7–42. CPRI_MAP_TX_READY_THR—CPRI Mapping Tx Ready Threshold—Offset: 0x12C
Field Bits Access Function Default
RSRV [31:4] UR0 Reserved. 28’h0
map_tx_ready_thr [3:0] RW
Threshold for assertion of the mapN_tx_ready signal in FIFO
mode, for all data channels N . The mapN_tx_ready signal is
asserted only after the Map Tx buffer for data channel N empties to
a level below this threshold value. All the MAP Tx buffers have the
same depth, 16.
4’h8
Table 7–43. CPRI_MAP_TX_START_THR—CPRI Mapping Tx Start Threshold—Offset: 0x130
Field Bits Access Function Default
RSRV [31:4] UR0 Reserved. 28’h0
map_tx_start_thr [3:0] RW
In FIFO mode, threshold for starting transmission from the MAP Tx
buffers for all data channels
N to the CPRI transmitter interface.
Data transmission from each MAP Tx buffer starts only after that
MAP Tx buffer fills beyond this threshold value. All the MAP Tx
buffers have the same depth, 16.
This register does not participate in data transfer coordination in
synchronous buffer mode or in the internally-clocked
synchronization mode.
4’h7
Table 7–44. CPRI_PRBS_CONFIG—PRBS Generation Pattern Configuration—Offset: 0x13C
Field Bits Access Function Default
RSRV [31:2] UR0 Reserved. 30'h0
prbs_mode [1:0] RW
PRBS loopback and pattern mode. Values are:
00: Normal mode (IQ samples, no loopback)
01: Counter sequence (internal loopback path)
10: PRBS 2 23 -1 inverted (internal loopback path)
11: Reserved
The PRBS mode is common to all antenna-carrier
interfaces.
2'h0
Table 7–45. CPRI_PRBS_STATUS—PRBS Data Validation Status—Offset: 0x140–0x144 (1)
Field Bits Access Function Default
PRBS_error [(N_MAP+15):16] RC
Indicates PRBS error detected on the
corresponding antenna-carrier interfaces.
16'h0
PRBS_valid [(N_MAP-1):0]] RC
Indicates a valid PRBS pattern on the
corresponding antenna-carrier receiver interfaces.
16'h0
Note to Table 7–45 :
(1) If this CPRI IP core has more than 16 antenna-carrier interfaces (N_MAP > 16), the status for antenna-carrier interfaces 0 through 15 is in the
register at offset 0x140, and the status for antenna-carrier interfaces 16 and up is in the register at offset 0x144. The maximum number of
antenna-carrier interfaces in the CPRI IP core is 24.