General Circuit Interface (GCI)
17-6
Am186™CC/CH/CU Microcontrollers User’s Manual
17.5.1.1
Transmitting Data
1. Configure the HDLC channels and time slot assigners to transmit the data. For details,
see Chapter 15, “High-Level Data Link Control (HDLC),” and Chapter 16, “HDLC
External Serial Interface Configuration (TSAs).”
2. Configure and activate the GCI channels:
a. If using the TIC bus access procedure, set the TICEN and TICAD bits in the GTIC
register. For information about the TIC bus access procedure, see “TIC Bus Support”
on page 17-16.
b. If transmitting Monitor channel data, set the applicable configuration options in the
GPCON register (the MCHEN, MCHSEL, and BRDIS bits).
c. If transmitting IC channel data, set the applicable configuration options in the GPCON
register (the ICSEL and BRDIS bits).
d. For CI/1 channel data, set the applicable configuration option in the GPCON register
(the BRDIS bit).
e. If the bus is in a deactivated state, activate the bus by setting the GCIACT bit in the
GPCON register. For details, see “GCI Bus Deactivation/Activation” on page 17-9.
3. Set the interrupts to be taken with the GIMSK register. Bits in this register enable
interrupts based on interrupts set in the GISTAT register. Corresponding bits must be
set in both registers for the interrupt to be taken. If an interrupt is disabled in GIMSK,
the status can still be read. Note that for each GCITD0 register write, if using the TIC
bus access procedure, the BAR bit must be taken into consideration.
4. Wait for the DCLST bit in the GISTAT register to be set, indicating the data clock has
been started by the master clock device.
5. If the bus was in a deactivated state, turn off the GCI activation request by clearing the
GCIACT bit in the GPCON register.
6. For monitor channel transmission, each Transmit Buffer Available Interrupt should write
new data into the transmit register until all data has been transmitted.
7. For monitor channel transmission, set the MEOMRQ bit in the GPCON register on the
last byte transmitted. This bit forces the monitor channel transmitter to send an EOM
when all data is written.
The outgoing MX bits and incoming MR bits held inactive for two or more frames indicates
that the Monitor channel is idle in the outgoing direction.
At the start of transmission, program the GPCON register to select one of the two monitor
channels. Then load data into the GCI Monitor Transmit Data (GMTD) register, which causes
the GCI controller to present the first data byte to the bus and to perform an inactive-to-
active transition of the outgoing MX bits. Placing data on the bus also generates the Monitor
channel transmit buffer available interrupt, indicating that the next data byte may be written
to the buffer. Outgoing MX bits remain active, and the data is repeated until an inactive-to-
active transition of the incoming MR bit is received.
In subsequent transmissions, all the following bytes to be transmitted are presented to the
bus coincident with an active-to-inactive transition of outgoing MX bits. The GCI
specification defines a general case in which the transmitter waits for an inactive-to-active
transition of incoming MR bits, and a maximum speed case in which the transmitter achieves
a higher transmission rate by anticipating the falling edge of incoming MR bits. After
transmitting the last byte of data, indicated by the GMTD register being empty and the
Содержание Am186 CC
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Страница 18: ...Table of Contents xviii Am186 CC CH CU Microcontrollers User s Manual...
Страница 24: ...Introduction xxiv Am186 CC CH CU Microcontrollers User s Manual...
Страница 39: ...Architectural Overview Am186 CC CH CU Microcontrollers User s Manual 1 15 Figure 1 6 32 Channel Linecard CH CC...
Страница 40: ...Architectural Overview 1 16 Am186 CC CH CU Microcontrollers User s Manual...
Страница 86: ...System Overview 3 36 Am186 CC CH CU Microcontrollers User s Manual...
Страница 92: ...Emulator Support 4 6 Am186 CC CH CU Microcontrollers User s Manual...
Страница 112: ...DRAM Controller 6 8 Am186 CC CH CU Microcontrollers User s Manual...
Страница 134: ...Interrupts 7 22 Am186 CC CH CU Microcontrollers User s Manual...
Страница 186: ...Programmable I O Signals 9 8 Am186 CC CH CU Microcontrollers User s Manual...
Страница 200: ...Watchdog Timer 11 6 Am186 CC CH CU Microcontrollers User s Manual...
Страница 232: ...Asynchronous Serial Ports UARTs 13 24 Am186 CC CH CU Microcontrollers User s Manual...
Страница 242: ...Synchronous Serial Port SSI 14 10 Am186 CC CH CU Microcontrollers User s Manual...
Страница 264: ...High Level Data Link Control HDLC 15 22 Am186 CC CH CU Microcontrollers User s Manual...
Страница 332: ...Universal Serial Bus USB 18 34 Am186 CC CH CU Microcontrollers User s Manual...
Страница 348: ...Register Summary A 16 Am186 CC CH CU Microcontrollers User s Manual...
Страница 376: ...Index Index 18 Am186 CC CH CU Microcontrollers User s Manual...