s908gz60cfa Freescale Semiconductor, Inc, s908gz60cfa Datasheet - Page 214

• Manufacturer Part Number: s908gz60cfa
• Description: M68hc08 Microcontrollers
• Manufacturer: Freescale Semiconductor, Inc

Enhanced Serial Communications Interface (ESCI) Module
14.8.8 ESCI Prescaler Register
The ESCI prescaler register (SCPSC) together with the ESCI baud rate register selects the baud rate for
both the receiver and the transmitter.
PDS2–PDS0 — Prescaler Divisor Select Bits
PSSB4–PSSB0 — Clock Insertion Select Bits
214
These read/write bits select the prescaler divisor as shown in
These read/write bits select the number of clocks inserted in each 32 output cycle frame to achieve
more timing resolution on the average prescaler frequency as shown in
PSSB4–PSSB0.
Address:
There are two prescalers available to adjust the baud rate. One in the ESCI
baud rate register and one in the ESCI prescaler register.
The setting of ‘000’ will bypass not only this prescaler but also the prescaler
divisor fine adjust (PDFA). It is not recommended to bypass the prescaler
while ENSCI is set, because the switching is not glitch free.
Reset:
Read:
Write:
MC68HC908GZ60 • MC68HC908GZ48 • MC68HC908GZ32 Data Sheet, Rev. 6
PSSB[4:3:2:1:0]
$0009
PDS2
Bit 7
0 0 0 0 0
0 0 0 0 1
0 0 0 1 0
0 0 0 1 1
0 0 1 0 0
0
Table 14-10. ESCI Prescaler Divisor Fine Adjust
Figure 14-18. ESCI Prescaler Register (SCPSC)
PDS[2:1:0]
0 0 0
0 0 1
0 1 0
0 1 1
1 0 0
1 0 1
1 1 0
1 1 1
Table 14-9. ESCI Prescaler Division Ratio
PDS1
6
0
0/32 = 0
1/32 = 0.03125
2/32 = 0.0625
3/32 = 0.09375
4/32 = 0.125
PDS0
5
0
Prescaler Divisor Fine Adjust (PDFA)
NOTE
NOTE
PSSB4
4
0
;
Prescaler Divisor (PD)
Bypass this prescaler
PSSB3
3
0
2
3
4
5
6
7
8
Table
PSSB2
2
0
14-9. Reset clears PDS2–PDS0.
Table
PSSB1
1
0
14-10. Reset clears
Freescale Semiconductor
PSSB0
Bit 0
0