GMS30C7201 Datasheet, PDF (196/352 Pages) Hynix Semiconductor – 60MHz operation frequency Low power consumption

Fast AMBA Peripherals
12-42
64
symbols
8 symbols
Preamble Start Flag
4 DDs
(8 bits)
Address
4 DDs
(8 bits)
Control
(optional)
8180 DDs
max
(2045
bytes)
16 DDs
(32 bits)
Data
CRC-32
8 symbols
Stop Flag
Start Flag |0000|1100|0000|1100|0110|0000|0110|0000|
|0000|1100|0000|1100|0000|0110|0000|0110|
Stop Flag
Preamble |1000|0000|1010|1000|... repeated 16 times
Figure 12-13: High Speed Serial Frame Format for IrDA Transmission (4.0Mbps)
The preamble, start, and stop flags are a mixture of symbols which contain either 0, 1, or 2
pulses within the four time-slots. Symbols with 0 and 2 pulses are used to construct flags since
they represent invalid data bit pairings (one pulse required per symbol to represent one of four
bit pairs). The preamble contains sixteen repeated transmissions of the four symbols: 1000 0000
1010 1000, the start flag contains one transmission of eight symbols: 0000 1100 0000 1100 0110
0000 0110 0000, and the stop flag contains one transmission of eight symbols: 0000 1100 0000
1100 0000 0110 0000 0110. The address, control, data, and CRC-32 all use the standard 4PPM
DDs described above.
Address Field
The 8-bit address field is used by a transmitter to target a select group of receivers when multiple
stations are connected to the same set of serial lines. The address allows up to 255 stations to be
uniquely addressed (00000000 to 11111110). The global address (11111111) is use to broadcast
messages to all stations. Serial port 1 contains an 8-bit register which is used to program a
unique address for broadcast recognition as well as a control bit to enable/disable the address
match function. Note that the address of received frames is stored in the receive buffer along
with normal data, and that it is transmitted and received starting with its LSB and ending with
its MSB.
Control Field
The IPC control field is 8-bits and is optional (as defined by the user). The FIr does not provide
any hardware decode support for the control byte, but instead treats all bytes between the
address and the CRC as data. Note that the control field is transmitted and received starting with
its LSB and ending with its MSB.
Data Field
The data field can be any length which is a multiple of 8-bits, from 0 to 2045 bytes. The user
determines the data field length according to the application requirements and transmission
characteristics of the target system. Usually a length is selected which maximizes the amount of
data which can be transmitted per frame, while allowing the CRC checker to be able to
consistently detect all errors during transmission. Note that the serial port does not contain any
GMS30C7201 Data Sheet