3-20
Computer Group Literature Center Web Site
PCCchip2
3
Tick Timer 2 Counter
The Tick Timer 2 Counter is a 32-bit read/write register located at address
$FFF42010. When enabled, it increments every microsecond. Software
may read or write the counter at any time.
Prescaler Count Register
The Prescaler Count Register is an 8-bit counter used to generate the 1
MHz clock for the two tick timers. This register is a read-only register
located at address $FFF42014. It increments to $FF at the BCLK
frequency, then it is loaded from the Prescaler Clock Adjust Register.
Prescaler Clock Adjust Register
Note
The PCCchip2 runs at half the MPU speed on the MVME177P.
For example, an MVME177P with a 50 MHz MPU will run the
PCCchip2 at 25 MHz.
The Prescaler Clock Adjust Register is an 8-bit read/write register located
at address $FFF42015. It is required to adjust the prescaler so that it
maintains a 1 MHz clock source for the tick timers, regardless of what
ADR/SIZ
$FFF42010 (32 bits)
BIT
31
. . .
0
NAME
Tick Timer 2 Counter
OPER
R/W
RESET
X
ADR/SIZ
$FFF42014 (8 bits)
BIT
31
. . .
24
NAME
Prescaler Count
OPER
R/W
RESET
X
Summary of Contents for MVME1X7P
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Page 90: ...1 64 Computer Group Literature Center Web Site Programming Issues 1 ...
Page 248: ...3 50 Computer Group Literature Center Web Site PCCchip2 3 ...
Page 286: ...4 38 Computer Group Literature Center Web Site MCECC Functions 4 ...
Page 288: ...A 2 Computer Group Literature Center Web Site Summary of Changes A ...
Page 316: ...Index IN 14 Computer Group Literature Center Web Site I N D E X ...