mc68hc912bl16 Freescale Semiconductor, Inc, mc68hc912bl16 Datasheet - Page 63

• Manufacturer Part Number: mc68hc912bl16
• Description: 16-bit Microcontroller
• Manufacturer: Freescale Semiconductor, Inc

CGTCFG — Clock Generator Test Register
TSTSMD — Test Mode of Slow Mode Divider
BCSS— Bus Clock Select Slow
When TSTSMD set, TSTOUT[3:0] shows the Slow Mode counter. Bits are not writable.
10.6 Clock Divider Chains
MC68HC912BL16TS/D
RESET:
SLDV3 SLDV2 SLDV1 SLDV0
Read and write in special mode. Bits 0-3 not writable.
Figure 13, Figure 14, Figure 15, and Figure 16 summarize the clock divider chains for the various pe-
ripherals on the MC68HC912BL16.
The “intwai” signal in Figure 13, or wait mode, is the only mechanism for choosing slow clocks versus
normal frequency clocks in normal operating modes.
0
0
0
1
1
1
1
1
1
1
1
0 = Not in Test Mode.
1 = Test slow divider. Internal divider states stored in TSTOUT[3:0]
0 = SYSCLK is derived from crystal clock EXTALi.
1 = SYSCLK is derived from Slow clock SLWCLK only in special mode.
TSTSMD
1
1
1
0
0
0
0
1
1
1
1
Bit 7
0
0
1
1
0
0
1
1
0
0
1
1
BCSS
6
0
Freescale Semiconductor, Inc.
Table 22 SLOW Mode Register Divider Rates
1
0
1
0
1
0
1
0
1
0
1
For More Information On This Product,
(SLOW * 2)
Divide By:
5
0
0
Go to: www.freescale.com
22
24
26
28
30
10
12
14
16
18
20
4
0
0
16MHz XTAL
Bus Rate w/
800 KHz
667 KHz
571 KHz
500 KHz
444 KHz
400 KHz
364 KHz
333 KHz
308 KHz
286 KHz
267 KHz
TSTOUT3 TSTOUT2 TSTOUT1 TSTOUT0
3
0
2
0
Bus Rate w/
8MHz XTAL
400 KHz
333 KHz
286 KHz
250 KHz
222 KHz
200 KHz
182 KHz
167 KHz
154 KHz
143 KHz
133 KHz
1
0
Bit 0
Bus Rate w/
4MHz XTAL
0
200 KHz
167 KHz
143 KHz
125 KHz
111 KHz
100 KHz
91 KHz
84 KHz
77 KHz
72 KHz
67 KHz
$00E1
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