Datasheet

Chapter 24 DG128 Port Integration Module (S12XDG128PIMV2)
MC9S12XDP512 Data Sheet, Rev. 2.21
998 Freescale Semiconductor
24.0.5.9 ECLK Control Register (ECLKCTL)
Read: Anytime.
Write: Anytime.
The ECLKCTL register is used to control the availability of the free-running clocks and the free-running
clock divider.
76543210
R
NECLK NCLKX2
0000
EDIV1 EDIV0
W
Reset
1
1. Reset values in emulation modes are identical to those of the target mode.
Mode
Dependent
1000000Mode
SS
01000000
Special
Single-Chip
ES
11000000
Emulation
Single-Chip
ST
01000000
Special
Test
EX
01000000
Emulation
Expanded
NS
11000000
Normal
Single-Chip
NX
01000000
Normal
Expanded
= Unimplemented or Reserved
Figure 24-11. ECLK Control Register (ECLKCTL)
Table 24-12. ECLKCTL Field Descriptions
Field Description
7
NECLK
No ECLK — This bit controls the availability of a free-running clock on the ECLK pin. Clock output is always
active in emulation modes and if enabled in all other operating modes.
0 ECLK enabled
1 ECLK disabled
6
NCLKX2
No ECLKX2 — This bit controls the availability of a free-running clock on the ECLKX2 pin. This clock has a fixed
rate of twice the internal bus clock. Clock output is always active in emulation modes and if enabled in all other
operating modes.
0 ECLKX2 is enabled
1 ECLKX2 is disabled
1–0
EDIV[1:0]
Free-Running ECLK Divider — These bits determine the rate of the free-running clock on the ECLK pin. The
usage of the bits is shown in Table 24-13. Divider is always disabled in emulation modes and active as
programmed in all other operating modes.