ZR36050 Просмотр технического описания (PDF) - Unspecified
Номер в каталоге
Компоненты Описание
Список матч
ZR36050 Datasheet PDF : 52 Pages
| |||
ADVANCE INFORMATION
ZR36050
Table 9. Effect of Reading the STATUS_1 Bits, RESET Pulse,
and the GO Command on the STATUS_1 Control Register.
DATRDY MRKDET RFM RFD END TCVOVF DATOVF
RESET
0
0
0
0
1
0
0
GO
-
0
0
0
0
0
0
Reading
0
*-
0
0
0
0
0
STATUS_1
register
* = MRKDET is reset to “0” when STATUS_0 is read.
STATUS_0 and INT_REQ_0 bits
In decoding, INT_REQ_0 and STATUS_0 are used to notify the
host when specified markers or marker segments have been
extracted from the compressed data and written in the internal
memory. The markers and marker segments that can be speci-
fied are APP, COM, DRI(RST), DQT, DHT, DNL, SOF and SOS.
The APP and COM bits allow the extraction of APP or COM
segments longer than 64 bytes, by activating INT after each 64
byte section until the whole segment has been extracted. In
encoding, only the APP and COM bits are used to control the
transfer of APP or COM segments longer than 64 bytes.
APP
COM
DRI
(RST)
DQT
DHT
DNL
SOF
SOS
Figure 31. Status_0 and INT_REQ_0 Bits
DATRDY MRKDET
0
RFM
RFD
END TCVOVF DATOVF
Figure 32. Status_1 Bits
DATRDY
0
0
RFM
RFD
END
1
1
Figure 33. INT_REQ_1 Bits
Bits of INT_REQ_1 and STATUS_1 are as follows:
DATRDY. This bit is used only in Slave mode Compressed Data
Transfer. It is a special case in that it activates DINT instead of
INT, and the processing does not stop. In the encoding process,
the status bit is set when new compressed data is ready in the
Compressed Data Input/Output register, and cleared when the
host reads the compressed data. In the decoding process, it is
set when the ZR36050 is ready to accept new compressed data,
and is cleared when the host reads the STATUS_1 register, or
reads from or writes into the Compressed Data Input/Output
register.
MRKDET. Marker Detected. This bit is used to notify the host
that one of the STATUS_0 bits has been set. MRKDET bit is set
whenever any of the STATUS_0 bits is updated, i.e. it is the “OR”
function of the STATUS_0 register bits. The host can determine
the status of the STATUS_0 register by merely reading this bit.
MRKDET does not have a corresponding bit in the INT_REQ_1
register and therefore does not generate an INT signal. Note that
the MRKDET is not cleared by reading the STATUS_1 register.
It is cleared when the STATUS_0 register is read.
RFM. Request For Markers. RFM is used to notify the host that
the ZR36050 is ready to process new marker segments. In
encoding and decoding modes, when the ZR36050 stops due to
interrupt activation of RFM, it reads the MARKERS_EN,
INT_REQ_1, and INT_REQ_2 registers again. In the encoding
process, RFM is set before the start of each scan,m except for
the first scan. This allows the host to add optional marker
segments to each scan, update the SOS marker segments in the
internal memory (if more than four scans are used – since the
internal memory has provisions for four scans), and change the
interrupt request registers for the following scan.
It is also set in Auto Bit Rate Control mode, at the end of the Sta-
tistical Pass. In the decoding process, it is set after the last
sample of the scan has appeared on the PIXEL bus. RFM is
cleared when the host reads the STATUS_1 register. A GO
command will resume all internal operations.
RFD. Request For Data is set when the ZR36050 has completed
processing of markers and is ready to input or output data on the
PIXEL bus.
END. Indicates the end of processing in encoding and decoding,
when the ZR36050 enters the Idle state. The END pin reflects
the state of the END status bit. The END status bit is cleared
when the host issues a GO command.
TCVOVF. Used only with OVF option. Indicates Target Code
Volume overflow. This status bit is set by the ZR36050 only if the
overflow detection option was selected. When the TCVOVF
status bit is set, the ZR36050 aborts the encoding process and
goes into the Idle state. This bit must be set to “1” by the host in
the INT_REQ_1 register after every RESET in encoding opera-
tion with the overflow option chosen. Refer toTable 4.
DATOVF. Indicates overflow of the internal coefficient buffers in
encoding operation. Overflow in the internal coefficient buffers
can only happen if the ZR36050 activated the STOP pin, and the
system did not respond in time by suspending the flow of image
data to the PIXEL bus at the end of the current block. When the
DATOVF status bit is set, the ZR36050 aborts the encoding
process and goes into the Idle state. This bit must be set to “1”
by the host in the INT_REQ_1 register after every RESET in
encoding operation.
TCV_NET Register
Target Net Code Volume. Used only with OVF option. When the
overflow option is chosen, the ZR36050 compares the accumu-
31
Share Link: 