Functional Description
14.3.2.16 Emulation Control
The emulation control input (EMUSUSP) and submodule emulation control registers allow CPSW_3G
operation to be completely or partially suspended. There are three CPSW_3G submodules that contain
emulation control registers (CPGMAC_SL1, CPGMAC_SL2, and CPDMA). The submodule emulation
control registers must be accessed to facilitate CPSW_3G emulation control. The CPSW_3G module
enters the emulation suspend state if all three submodules are configured for emulation suspend and the
emulation suspend input is asserted.
A partial emulation suspend state is entered if one or two submodules is configured for emulation suspend
and the emulation suspend input is asserted. Emulation suspend occurs at packet boundaries. The
emulation control feature is implemented for compatibility with other peripherals.
CPGMAC_SL Emulation Control
The emulation control input (TBEMUSUP) and register bits (soft and free in the EMControl register) allow
CPGMAC_SL operation to be suspended. When the emulation suspend state is entered, the
CPGMAC_SL will stop processing receive and transmit frames at the next frame boundary. Any frame
currently in reception or transmission will be completed normally without suspension. For receive, frames
that are detected by the CPGMAC_SL after the suspend state is entered are ignored. Emulation control is
implemented for compatibility with other peripherals.
CPDMA Emulation Control
The emulation control input (TBEMUSUP) and register bits (soft and free in the EMControl register) allow
CPDMA operation to be suspended. When the emulation suspend state is entered, the CPDMA will stop
processing receive and transmit frames at the next frame boundary. Any frame currently in reception or
transmission will be completed normally without suspension. For transmission, any complete or partial
frame in the tx cell fifo will be transmitted. For receive, frames that are detected by the CPDMA after the
suspend state is entered are ignored. No statistics will be kept for ignored frames. Emulation control is
implemented for compatibility with other peripherals
The following table shows the operations of the emulation control input and register bits:
Table 14-18. Operations of Emulation Control Input and Register Bits
EMUSUSP
soft
free
Description
0
X
X
Normal Operation
1
0
0
Normal Operation
1
1
0
Emulation Suspend
1
X
1
Normal Operation
14.3.2.17 Software IDLE
The submodule software idle register bits enable CPSW_3G operation to be completely or partially
suspended by software control. There are three CPSW_3G submodules that contain software idle register
bits (CPGMAC_SL1, CPGMAC_SL2, and CPDMA). Each of the three submodules may be individually
commanded to enter the idle state. The idle state is entered at packet boundaries, and no further packet
operations will occur on an idled submodule until the idle command is removed. The CPSW_3G module
enters the idle state when all three submodules are commanded to enter and have entered the idle state.
Idle status is determined by reading or polling the three submodule idle bits. The CPSW_3G is in the idle
state when all three submodules are in the idle state. The CPSW_Soft_Idle bit may be set if desired after
the submodules are in the idle state. The CPSW_Soft_Idle bit causes packets to not be transferred from
one FIFO to another FIFO internal to the switch.
14.3.2.18 Software Reset
The CPSW_3G software reset register, CPSW_3GSS software reset register and the three submodule
software reset registers enable the CPSW_3GSS to be reset by software. There are three CPSW_3G
submodules that contain software reset registers (CPGMAC_SL1, CPGMAC_SL2, and CPDMA). Each of
the three submodules may be individually commanded to be reset by software.
1210
Ethernet Subsystem
SPRUH73H – October 2011 – Revised April 2013
Copyright © 2011–2013, Texas Instruments Incorporated