UPSD3354DV-40U6 Datasheet, PDF (159/272 Pages) STMicroelectronics – fast 8032 MCU with programmable logic

UPSD33xx
Programmable counter array (PCA) with PWM
26.10
PWM mode - fixed frequency, 10-bit
The 10-bit PWM logic requires that all 3 TCMs in PCA0 or PCA1 operate in the same 10-bit
PWM mode. The 10-bit PWM operates in a similar manner as the 16-bit PWM, except the
PCACHm and PCACLm counters are reconfigured as 10-bit counters. The CAPCOMHn and
CAPCOMLn registers become 10-bit registers.
PWM duty cycle of each TCM module can be specified in the 10-bit CAPCOMHn and
CAPCOMLn registers. When the 10-bit PCA counter is equal or greater than the values in
the 10-bit registers CAPCOMHn and CAPCOMLn, the PWM output switches to a high state.
When the 10-bit PCA counter overflows, the PWM pin is switched to a logic low and starts
the next PWM pulse.
The most-significant 6 bits in the PCACHm counter and CAPCOMH register are “Don’t
cares” and have no effect on the PWM generation.
26.11 Writing to capture/compare registers
When writing a 16-bit value to the PCA Capture/Compare registers, the low byte should
) _{always be written first. Writing to CAPCOMLn clears the E_COMP Bit to '0'; writing to}
t(s ^{CAPCOMHn sets E_COMP to '1' the largest duty cycle is 100% (CAPCOMHn CAPCOMLn}
c _{= 0x0000), and the smallest duty cycle is 0.0015% (CAPCOMHn CAPCOMLn = 0xFFFF). A}
u _{0% duty cycle may be generated by clearing the E_COMP Bit to ‘0’.}
ct(s) ^{- Obsolete Prod 26.12}
Control register bit definition
Each PCA has its own PCA_CONFIGn, and each module within the PCA block has its own
TCM_Mode register which defines the operation of that module (see Table 103 on page 159
through Table 105 on page 160). There is one PCA_STATUS register that covers both PCA0
and PCA1 (see Table 107 on page 161).
Table 103. PCA0 Control register PCACON0 (SFR 0A4h, Reset Value 00h)
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
EN-ALL EN_PCA EOVFI PCAIDLE
–
10B_PWM
CLK_SEL[1:0]
rodu _{Table 104. PCACON0 register bit definition}
P_Bit
Symbol
Function
te _{0 = No impact on TCM modules}
le _{1 = Enable both PCA counters simultaneously}
so ₇
EN-ALL
(override the EN_PCA Bits)
b _{This bit is to start the two 16-bit counters in the}
O PCA. For customers who want 5 PWM, for
example, this bit can start all of the PWM outputs.
0 = PCA counter is disabled
1 = PCA counter is enabled
6
EN_PCA
EN_PCA Counter Run Control Bit. Set with
software to turn the PCA counter on. Must be
cleared with software to turn the PCA counter off.
Doc ID 9685 Rev 7
159/272