User Manual
BCM1250/BCM1125/BCM1125H
10/21/02
B r o a d c o m C o r p o r a t i o n
Document
1250_1125-UM100CB-R
Section 10: Serial Interfaces Page
353
S
YNCHRONOUS
S
ERIAL
R
EGISTER
S
UMMARY
All configuration and control registers are 16 bits.
Table 231: Serial Mode Configuration Register
ser_mode_0 -
00_1006_0500
ser_mode_1 -
00_1006_0900
Bits
Name
Default
Descriptions
Data Format Related
0
crc_mode
1’b0
0: CRC-CCITT.
1: CRC-32.
1
msb_first
1’b0
0: Transmit/Receive LSB in each byte first.
1: Transmit/Receive MSB in each byte first.
This bit is only used in transparent mode.
HDLC Related
5:2
flag_num
3’b1
Minimum number of Flags sent between Back-to-Back frames if HDLC is enabled.
A value of 0 indicates the trailing Flag of the previous frame is used as the Open
Flag of the next frame.
6
flag_en
1’b0
0: Idle is sent when Transmit module is Idle.
1: Flag is sent when Transmit module is Idle.
7
hdlc_en
1’b1
0: Transparent mode.
1: HDLC encoding.
Loopback
8
loop_strobe
1’b0
Loopback Strobe mode. This configures the Sync/Enable inputs during loopback.
0: TIN and RIN are taken from the external source.
1: TIN is always active and RIN is internally connected to RtsTstrobe.
9
loop_data
1’b0
Loopback enable. If this bit is set the DIN input be internally connected to the DOUT
output to allow loopback testing.
15:10
reserved
6’bx
Reserved
63:16
notimp
48’bx
Not Implemented.
Table 232: Synchronous Serial Clock Source and Line Interface Mode Register
ser_line_mode_0 -
00_1006_0578
ser_line_mode_1 -
00_1006_0978
Bits
Name
Default
Description
0
rx_clk_inv
1’b0
This bit controls the inverter on the receive clock.
0: Not inverted (clock on rising edge).
1: Inverted (clock on falling edge).
1
rx_clk_src
1’b0
Receiver clock source.
0: Internal clock, generated by the baud rate generator.
1: External clock from CIN_RCLKIN pin.
3:2
rx_sync_delay
2’b0
Number of clock delays between the Frame Sync/Enable and the first bit of the
frame.
4
rx_sync_active
1’b0
0: Sync/Enable is active high.
1: Sync/Enable is active low.
5
rx_strobe_active
1’b0
0: Strobe in Line Interface is active high.
1: Strobe in Line Interface is active low.