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Nations Technologies Inc.
Tel
:
+86-755-86309900
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Address: Nations Tower, #109 Baoshen Road, Hi-tech Park North.
Nanshan District, Shenzhen, 518057, P.R.China
Idle
This state is an idle state. After the system is reset, the state is ready to send a command or the command state machine
(CPSM) is turned off. All belong to the Idle state. When the command state machine (CPSM) is enabled, wait for the
end of data transmission bit (SDIO_CMDCTRL.WDATEND) Enable or disable can enter the Pend state.
Note: The command state machine remains idle for at least 8 SDIO_CLK cycles to meet NCC and NRC timing
constraints. NCC is the minimum time interval between two host commands, and NRC is the minimum time interval
between a host command and a card response.
Pend
This state is a pending state, waiting for the end of data transfer. When the data transmission is completed, the
command state machine enters the Send state from the Pend state; when the command state machine (CPSM) is
turned off, the CPSM enters the Idle state.
Send
This state is the sending state, indicating that the command is being sent. If there is a response after the command is
sent, the command state machine enters the Wait state, and if there is no response after the command is sent, the
command state machine enters the Idle state.
Wait
This state is a wait state, waiting for the response start bit. When entering the wait (Wait) state, the command timer
starts to run; if a response is received, that is, the start bit is detected, the command state machine (CPSM) enters the
Receive state, and when the command state machine (CPSM) enters the receiving (Receive) state Before a timeout
occurred, set the timeout flag and enter the Idle state.
Note: The command timeout period is fixed at 64 SDIO_CLK clock cycles.
Receive
This state is the receiving state, the response is received and the CRC is checked.
After receiving the response in CE-ATA mode, disable the CE-ATA interrupt and wait for the CE-ATA device
command completion signal to be enabled and then enter the Wait_CPL state.
Receive a response in CE-ATA mode, disable the CE-ATA interrupt and wait for the CE-ATA device command
completion signal to disable and enter the Pend state.
The Idle state is entered when the CPSM is closed, a response is received, or the command CRC detection fails.
Wait_CPL
In this state, wait for the CE-ATA device command completion signal, and enter the Idle state after receiving the CE-
ATA command completion signal. It will also enter the Idle state when the CPSM is turned off or the command CRC
check fails.
If the interrupt bit is set in the command register, the timer is turned off and the CPSM waits for an interrupt request
from a certain card. If the pending bit is set in the command register, the CPSM enters the pending (Pend) state and
waits for the CmdPend signal sent by the data channel subunit. When the CmdPend signal is detected, the CPSM
enters the sending (Send) state, which will trigger the data counter to stop sending function of the command.