MC68HC908GP32CB Freescale Semiconductor, MC68HC908GP32CB Datasheet - Page 66

• Manufacturer Part Number: MC68HC908GP32CB
• Description: IC MCU 32K FLASH 8MHZ 42-SDIP
• Manufacturer: Freescale Semiconductor
• Series: HC08r

Specifications of MC68HC908GP32CB

• Core Processor: HC08
• Core Size: 8-Bit
• Speed: 8MHz
• Connectivity: SCI, SPI
• Peripherals: LVD, POR, PWM
• Number Of I /o: 33
• Program Memory Size: 32KB (32K x 8)
• Program Memory Type: FLASH
• Ram Size: 512 x 8
• Voltage - Supply (vcc/vdd): 2.7 V ~ 5.5 V
• Data Converters: A/D 8x8b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 42-DIP (0.600", 15.24mm)
• For Use With: M68EVB908GP32 - BOARD EVALUATION FOR HC908GP32
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Eeprom Size: -

Clock Generator Module (CGM)
66
4. Select a VCO frequency multiplier, N.
5. If N is < N
6. Calculate and verify the adequacy of the VCO and bus frequencies f
7. Select the VCO’s power-of-two range multiplier E, according to this table:
8. Select a VCO linear range multiplier, L, where f
When the tolerance on the bus frequency is tight, choose f
and R = 1. If f
practical choices of f
Reduce N/R to the lowest possible R.
Then recalculate N:
max
, use P = 0. If N > N
RCLK
NOTE: Do not program E to a value of 3.
R
cannot meet this requirement, use the following equation to solve for R with
RCLK
=
round R
19,660,800 ≤ f
9,830,400 ≤ f
, and choose the f
N max
N max
MC68HC908GP32 Data Sheet, Rev. 10
0 < f
N max
Frequency Range
N
MAX
f
N
VCLK
L
VCLK
max
=
Current N Value
0
×
×
=
=
<
VCLK
×
round
VCLK
<
2
4
f
, choose P using this table:
< 9,830,400
round
round
N
BUS
⎧
⎨
⎩
<
<
N
=
⎛
⎜
⎝
≤
f
------------------------- -
N
N
< 19,660,800
VCLKDES
≤
(
< 39,321,600
N max
2
f
⎛
⎜
⎝
N max
≤
≤
RCLK
=
P
R f
------------------------------------ -
⎛
⎜
⎝
⎛
⎜
⎝
RCLK
N max
N max
--------------------------
2
R f
------------------------------------ -
×
(
×
f
f
E
VCLK
N R
f
×
RCLK
f
VCLK
×
VCLKDES
RCLK
NOM
⁄
VCLKDES
f
×
⎞
⎟
⎠
that gives the lowest R.
NOM
2
×
×
–
) f
) 4 ⁄
×
×
integer
4
8
= 38.4 kHz
⎞
⎟
⎠
2
RCLK
P
⎞
⎟
⎠
⎞
⎟
⎠
RCLK
⎛
⎜
⎝
f
------------------------- -
VCLKDES
P
0
1
2
3
f
RCLK
to an integer divisor of f
E
0
1
2
VCLK
⎞
⎟
⎠
⎫
⎬
⎭
and f
Freescale Semiconductor
BUS
.
BUSDES
,