Datasheet

Chapter 10 XGATE (S12XGATEV3)
MC9S12XE-Family Reference Manual Rev. 1.25
Freescale Semiconductor 355
• Provides up to 108 XGATE channels, including 8 software triggered channels
• Interruptible thread execution
• Two register banks to support fast context switching between threads
• Hardware semaphores which are shared between the S12X_CPU and the XGATE module
• Able to trigger S12X_CPU interrupts upon completion of an XGATE transfer
• Software error detection to catch erratic application code
10.1.3 Modes of Operation
There are four run modes on S12XE devices.
• Run mode, wait mode, stop mode
The XGATE is able to operate in all of these three system modes. Clock activity will be
automatically stopped when the XGATE module is idle.
• Freeze mode (BDM active)
In freeze mode all clocks of the XGATE module may be stopped, depending on the module
configuration (see Section 10.3.1.1, “XGATE Control Register (XGMCTL)”).
10.1.4 Block Diagram
Figure 10-1 shows a block diagram of the XGATE.
Figure 10-1. XGATE Block Diagram
Interrupts
XGATE
Requests
S12X_MMC
XGATE
Peripherals
Semaphores
Software Triggers
Peripheral Interrupts
S12X_DBG
Data/Code
Software
Triggers
XGATE
S12X_INT
SWE
Interrupt
RISC Core
Software Error Logic
Interrupt Flags
(XGIF)