System flag register 2 (sysflg2), System flag register 2 (sysflg2) -12, Input, latched during – Cirrus Logic EP73xx User Manual
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EP7309/11/12 User’s Manual - DS508UM4
Copyright Cirrus Logic, Inc. 2003
System Registers
5
System Flag Register 2 (SYSFLG2)
Address:
0x8000.1140, Read Only
Definition:
The SYSFLG2 system flag register is a 32-bit read only register. It
provides information regarding the status of the CPU and associated
peripherals.
Bit Descriptions:
SS2RXOF: Master/slave SSI2 RX FIFO overflow. This bit is set when a write
is attempted to a full RX FIFO (i.e., when RX is still receiving data
and the FIFO is full). This can be cleared in one of two ways:
1) Empty the FIFO (remove data from FIFO) and then
write to
SRXEOF location.
2) Disable the RX (affects of disabling the RX will not take
place until a full SSI2 clock cycle after it is disabled)
RESVAL:
Master/slave SSI2 RX FIFO residual byte present, cleared by
popping the residual byte into the SSI2 RX FIFO or by a new RX
frame sync pulse.
RESFRM:
Master/slave SSI2 RX FIFO residual byte present, cleared only by
a new RX frame sync pulse.
SS2RXFE: Master/slave SSI2 RX FIFO empty bit. This will be set if the
16 x 16 RX FIFO is empty.
SS2TXFF:
Master/slave SSI2 TX FIFO full bit. This will be set if the 16 x 16
TX FIFO is full. This will get cleared when data is removed from
the FIFO or the EP73xx is reset.
SS2TXUF: Master/slave SSI2 TX FIFO Underflow bit. This will be set if there
is attempt to transmit when TX FIFO is empty. This will be cleared
when FIFO gets loaded with data.
CKMODE: This bit reflects the status of the
CLKSEL
(
PE[2]
) input, latched
during
nPOR
. When low, the PLL is running and the chip is
operating in 18.432–73.728 MHz mode. When high the chip is
operating from an external 13 MHz clock.
UBUSY2:
UART2 transmitter busy. This bit is set while UART2 is busy
transmitting data; it is guaranteed to remain set until the complete
byte has been sent, including all stop bits.
31
30
29
28
27
26
25
24
23
22
21
20
19
18
17
16
RSVD
UTXFF2
URXFE2
RSVD
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
RSVD
UBUSY
2
RSVD
CKMOD
E
SS2TXU
F
SS2TXF
F
SS2RXF
E
RESFR
M
RESVAL
SS2RX
OF