MC9S12XD256MAL Datasheet, PDF (802/1348 Pages) Freescale Semiconductor, Inc – Freescale’s Scalable Controller Area Network

Chapter 21 External Bus Interface (S12XEBIV2)
21.5.2.1 Example 2a: Emulation Single-Chip Mode
This mode is used for emulation systems in which the target application is operating in normal single-chip
mode.
Figure 21-5 shows the PRU connection with the available external bus signals in an emulator application.
S12X_EBI
ADDR[22:0]/IVD[15:0]
DATA[15:0]
Emulator
EMULMEM
LSTRB
R/W
PRU
PRR
Ports
ADDR[22:20]/ACC[2:0]
ADDR[19:16]/
IQSTAT[3:0]
ECLK
ECLKX2
Figure 21-5. Application in Emulation Single-Chip Mode
The timing diagram for this operation is shown in:
• Figure ‘Example 2a: Emulation Single-Chip Mode — Read Followed by Write’
The associated timing numbers are given in:
• Table ‘Example 2a: Emulation Single-Chip Mode Timing (EWAITE = 0)’
Timing considerations:
• Signals muxed with address lines ADDRx, i.e., IVDx, IQSTATx and ACCx, have the same timing.
• LSTRB has the same timing as R/W.
• ECLKX2 rising edges have the same timing as ECLK edges.
• The timing for accesses to PRU registers, which take 2 cycles to complete, is the same as the timing
for an external non-PRR access with 1 cycle of stretch as shown in example 2b.
MC9S12XDP512 Data Sheet, Rev. 2.21
804
Freescale Semiconductor