Cypress CY7C602xx Network Card User Manual


 
CY7C601xx, CY7C602xx
Document 38-16016 Rev. *E Page 27 of 68
Table 12-5. Timer Clock Configuration (TMRCLKCR) [0x31] [R/W]
Bit # 7 6 5 4 3 2 1 0
Field TCAPCLK Divider TCAPCLK Select ITMRCLK Divider ITMRCLK Select
Read/Write R/W R/W R/W R/W R/W R/W R/W R/W
Default 1 0 0 0 1 1 1 1
Bit [7:6]: TCAPCLK Divider [1:0]
TCAPCLK Divider controls the TCAPCLK divisor.
0 0 = Divider Value 2
0 1 = Divider Value 4
1 0 = Divider Value 6
1 1 = Divider Value 8
Bit [5:4]: TCAPCLK Select
The TCAPCLK Select field controls the source of the TCAPCLK.
0 0 = Internal 24 MHz Oscillator
0 1 = External Crystal Oscillator—external crystal oscillator on CLKIN and CLKOUT if the external crystal oscillator is enabled,
CLKIN input if the external crystal oscillator is disabled (the XOSC Enable bit of the CLKIOCR Register is cleared—Table 12-4.)
1 0 = Internal 32 kHz Oscillator
1 1 = TCAPCLK Disabled
Note The 1024 μs interval timer is based on the assumption that TCAPCLK is running at 4 MHz. Changes in TCAPCLK frequency
cause a corresponding change in the 1024 μs interval timer frequency.
Bit [3:2]: ITMRCLK Divider
ITMRCLK Divider controls the ITMRCLK divisor.
0 0 = Divider value of 1
0 1 = Divider value of 2
1 0 = Divider value of 3
1 1 = Divider value of 4
Bit [1:0]: ITMRCLK Select
0 0 = Internal 24 MHz Oscillator
0 1 = External crystal oscillator—external crystal oscillator on CLKIN and CLKOUT if the external crystal oscillator is enabled,
CLKIN input if the external crystal oscillator is disabled.
1 0 = Internal 32 kHz Oscillator
1 1 = TCAPCLK
Note Changing the source of TMRCLK requires both the source and destination clocks to be running. It is not possible to change
the clock source away from TCAPCLK after that clock is stopped.
[+] Feedback [+] Feedback