BCM1250/BCM1125/BCM1125H
User Manual
10/21/02
B r o a d c o m C o r p o r a t i o n
Page
328
Section 10: Serial Interfaces
Document
1250_1125-UM100CB-R
6
duart_frm_err
1'b0
Frame error: This flag tags a received character to indicate that this character
(including parity bit) was non-zero and did not have a valid stop bit.
7
duart_rcvd_brk
1'b0
Received break: This flag tags a received character (which will be zero) to indicate
that a the start of a break was detected.
63:8
notimp
56’bx
Not implemented.
Table 200: DUART Status Registers
(Cont.)
duart_status_a -
00_1006_0120
duart_status_b -
00_1006_0220
READ ONLY
Bits
Name
Default
Description
Table 201: DUART Baud Rate Clock Registers
duart_clk_sel_a -
00_1006_0130
duart_clk_sel_b -
00_1006_0230
Bits
Name
Default
Description
11:0
uart_clk_counter
12'h0
Baud rate counter. This register sets the baud rate for both the transmitter and
receiver. Set to (100 MHz/(baud rate * 20))-1.
63:12
notimp
52’bx
Not implemented.
Table 202: DUART Full Interrupt Control Registers
duart_full_ctl_a -
00_1006_0140
duart_full_ctl_b -
00_1006_0240
Bits
Name
Default
Description
3:0
duart_sig_full
4'hF
This field sets the threshold for the receive fifo full interrupt. The interrupt is raised
when the number of characters in the fifo is greater than the value set.
With the default of 15 the interrupt is only raised when the fifo is completely full.
7:4
duart_int_time
4'h0
If this field is non-zero then the fifo full interrupt is raised if there are any characters
in the receive fifo and the receive data line has been idle for duart_int_time * 16
bit times.
If this field is zero the interrupt is never raised by a timeout.
The timeout interrupt is cleared by any read of the
rx_hold
register.
63:8
notimp
56b'x
Not Implemented.
Table 203: DUART Received Data Registers
duart_rx_hold_a -
00_1006_0160
duart_rx_hold_b -
00_1006_0260
READ ONLY, Read pops character from FIFO
Bits
Name
Default
Description
7:0
rx_data
8'hx
Read Only. Received data. The character is only valid if the duart_rx_rdy bit is
set in the status register prior to this register being read, when this register is read
the next character is made available and its flag bits will be made available in the
duart_status register.
63:8
notimp
56’bx
Not implemented.