PXR40RM Datasheet, PDF (957/1434 Pages) Freescale Semiconductor, Inc – PXR40 Microcontroller

Enhanced Serial Communication Interface (eSCI)
triggered by the module are shown in Table 26-27. The state diagram of the transmitter is shown in
Figure 26-25.
RESET_STATE
Idle
halt
Stop
EN
EN
DIS
done
Run
DIS
Ready
start
Figure 26-25. Transmitter State Diagram
The current state of the transmitter can be determined by the TE control bit in the Control
Register 1 (eSCI_CR1) and the TACT status bit in Interrupt Flag and Status Register 1 (eSCI_IFSR1).
Table 26-25. Transmitter States
State
Idle
Ready
Run
Stop
Indication
eSCI_CR1[TE] eSCI_IFSR1[TACT]
Description
0
0
Transmitter is disabled and no transmission is running
1
0
Transmitter is enabled and no transmission is running
1
1
Transmitter is enabled and transmission is running
0
1
Transmitter is disabled and transmission is running
The application triggers a transition described in Table 26-26 when it issues a command by writing to the
TE bit in the Control Register 1 (eSCI_CR1). The transition is triggered only if the conditions are fulfilled.
As a result of the transition the state of the transmitter is changed as shown in Figure 26-25 and the action
given in Table 26-26 is executed.
Table 26-26. Transmitter Application Transitions
Transition
EN
DIS
Command
Precondition
eSCI_CR1[TE]:=1 eSCI_CR1[TE]=0
eSCI_CR1[TE]:=0 eSCI_CR1[TE]=1
Action
iPRE:=1
Description
Transmitter is enabled by application command.
Transmitter is disabled by application command
The module transition shown in Table 26-27 are triggered when the described condition or event occurs.
The send break bit SBK in the Control Register 1 (eSCI_CR1) is check for the start condition. The internal
commit bit iCMT, the transmitter active bit TACT in the Interrupt Flag and Status Register 1
(eSCI_IFSR1), the TDRE, and the TC flag in the Interrupt Flag and Status Register 1 (eSCI_IFSR1) are
changed as a action result of the transition.
Freescale Semiconductor
PXR40 Microcontroller Reference Manual, Rev. 1
26-29