MOTOROLA
PROGRAMMING REFERENCE
MMC2001
C-22
REFERENCE MANUAL
SHEN — Show Cycle Enable
These two bits are used to determine what the EIM does with the external bus during
internal transfers (i.e., an access to the internal ROM, RAM or peripherals). When
show cycles are enabled, the internal address and data bus are driven externally. On
reset, show cycles are disabled.
C.6 PWM Module
This section describes the registers and control bits in the PWM module. All registers
reset to 0x0000.
These registers must be accessed with halfword accesses. Accesses other than half-
word in size result in undefined activity.
Table C-9 Show Cycle Enable Field Settings
Value
Meaning
00
Show cycles disabled. The external address bus is driven with the last valid
external address, and the data bus values are held by bus keepers.
01
Show cycles enabled. Internal termination to the CPU during idle cycles caused
by EDC or CSA being set follows normal operation. This means that internal
transfers that occur during EDC/CSA idle cycles will not be visible externally.
10
Show cycles enabled. Internal termination to the CPU during idle cycles caused
by EDC or CSA being set is delayed by one clock. This ensures that all internal
transfers can be externally monitored, at the expense of performance.
11
Reserved
Table C-10 PWM Address Map
Address
Use
Access
10005000
PWM0 Control Register (PWMCR0)
Supervisor Only
10005002
PWM0 Period Register (PWMPR0)
Supervisor Only
10005004
PWM0 Width Register (PWMWR0)
Supervisor Only
10005006
PWM0 Counter Register (PWMCTR0)
Supervisor Only
10005008
PWM1 Control Register (PWMCR1)
Supervisor Only
1000500A
PWM1 Period Register (PWMPR1)
Supervisor Only
1000500C
PWM1 Width Register (PWMWR1)
Supervisor Only
1000500E
PWM1 Counter Register (PWMCTR1)
Supervisor Only
10005010
PWM2 Control Register (PWMCR2)
Supervisor Only
10005012
PWM2 Period Register (PWMPR2)
Supervisor Only
10005014
PWM2 Width Register (PWMWR2)
Supervisor Only
10005016
PWM2 Counter Register (PWMCTR2)
Supervisor Only
10005018
PWM3 Control Register (PWMCR3)
Supervisor Only
1000501A
PWM3 Period Register (PWMPR3)
Supervisor Only
1000501C
PWM3 Width Register (PWMWR3)
Supervisor Only
1000501E
PWM3 Counter Register (PWMCTR3)
Supervisor Only
10005020
PWM4 Control Register (PWMCR4)
Supervisor Only
10005022
PWM4 Period Register (PWMPR4)
Supervisor Only
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Freescale Semiconductor, Inc.
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